JPH0642977B2 - Gas curing type mold making equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial 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 into the mold to remove the The present invention relates to an improvement in a gas hardening type mold making apparatus that hardens molding sand to mold a mold.

(Prior Art) In general, a molding sand is molded by blowing a molding sand kneaded with a binder into a mold and then injecting a hardening gas into the molding sand to cure the molding sand. 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 an invention of Japanese Patent Publication No. 48-9246.

As shown in FIG. 6, a slide shutter 1 is slidably mounted in a slide case 2 fixed below a blow box 4, and a molding material is blown into the slide shutter 1. A reaction catalyst gas injection port 6 is formed which penetrates the hole 5 and communicates with the reaction catalyst gas conduit 8 connected to one side of the shutter 1 through the gas passage 7 and is open only to the pattern 9 side. It has been configured.

According to this, first, the molding material injection hole 5 formed in the slide shutter 1 is aligned with the injection 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 slide the shutter 1 as shown in the drawing so that the molding material filling port of the pattern 9 and the reaction catalyst gas injection hole 6 in the shutter 1 are aligned with each other, so that the reaction catalyst gas conduit 8 and the gas The reaction catalyst gas blown out through the passage 7 is patterned 9
While spraying on the molding material therein, the molding material is cured to mold a temporary sand mold for casting. This allows
After the injection of the molding material, the gassing step can be performed at the same position without moving the pattern 9 or the blow tank 4, so that the time required for the molding step can be shortened.

(Problems to be solved by the invention) By the way, in the above-mentioned conventional example, in order to perform the blowing process and the gassing process at the same position, the slide shutter 1 mounted in the slide case 2 is adapted to each process. The slide shutter 1 is slidable with respect to the slide case 2 as described above, and further, between the slide shutter 1 and the slide case 2 during the gassing process. It is very difficult to add a sealing function to prevent the reaction catalyst gas (curing gas) from leaking to the outside. Moreover, since the slide shutter 1 slides in the slide case 2, it is difficult to avoid wear of both of them. In particular, the molding material in the blow tank 4, that is, unused molding sand, slides between the slide shutter 1 and the slide case. If it gets caught between the two, the wear of both is further promoted.

In this case, the reaction catalyst gas (hardening gas) supplied into the slide shutter 1 during the gassing process.
However, it leaks to the outside from between the shutter 1 and the slide case 2, which causes deterioration of the working environment and
In particular, when the gas flows into the blow tank 4 through the blow hole 3 formed in the upper portion of the slide case 2, the unused foundry sand stored in the tank 4 is hardened. , It was supposed to hinder the subsequent blowing process.

Further, in the above-mentioned conventional example, the blowing process and the gassing process are performed at the same position to shorten the manufacturing time of this type of mold, but the mold cured after the gassing process is finished. In the case of taking out, the entire blow tank 4 including the slide case 2 and the slide shutter 1 attached thereto or at least one of the patterns 9 is moved to another station and then separately provided. The mold that has been cured and molded using the take-out mechanism must be taken out from within the pattern 9. Therefore, although the blowing process and the gassing process are performed at the same position to reduce the working time, the eject process must be performed at another station after each process. However, it becomes impossible to significantly reduce the manufacturing time of this seed mold, and since it is necessary to separately prepare a take-out mechanism as described above, this seed molding apparatus becomes large in size.

Therefore, in the present invention, in a gas hardening type mold making apparatus for molding a sand mold for casting by using a cold box method, it is possible to perform not only a blowing step and a gassing step but also an eject step at the same station, and a hardening step at the time of the gassing step. Gas leaks to the outside, especially
An object of the present invention is to provide a mold making apparatus capable of reliably preventing the hardening gas from flowing into the sand tank.

(Means for Solving Problems) In order to achieve the above-mentioned object, the present invention is characterized in that it is configured as follows.

That is, after the molding sand stored in the sand tank is filled in the mold through the blow hole provided on the lower surface of the tank, a hardening gas is injected into the molding sand in the mold to cure the molding sand. In a gas hardening type mold making apparatus configured to mold a mold by hardening the mold, a casting sand filling port provided on the upper surface of the mold mounted around the blow hole provided on the lower surface of the sand tank. A blow chip made of an elastic material that is in contact with the sand tank and a gassing case are provided outside the sand tank so as to be vertically movable relative to the blow tank. Thus, when the lower end surface of the gassing case is brought into contact with the upper surface of the mold and the blow tip is separated from the filling port of the mold, a cavity formed in the mold through the filling port. And a gas supply chamber communicating with the gas supply chamber.

On the other hand, an eject pin is disposed in the sand tank so as to face a blow hole provided on the lower surface of the tank, and the tip of the eject pin penetrates the blow tip from a position retracted upward. By providing an extruding means that is driven to a position projecting downward, when the curing gas is introduced into the gas supply chamber formed by the gassing case and the outside of the sand tank and the upper surface of the mold,
That is, in the gassing step, the eject pin is projected into the blow tip, and the outer peripheral surface of the tip is in close contact with the inner peripheral surface of the blow tip.

(Operation) According to the above configuration, after the lower end surface of the gassing case and the upper surface of the mold are brought into close contact with each other, the blow tip made of an elastic material mounted around the blow hole in the sand tank is attached to the mold. By contacting the foundry sand filling port provided in, the compressed air is introduced into the sand tank with the filling port and the blow hole communicating with each other and the eject pin retracted upward, The foundry sand in the tank is blown into the mold to fill the cavity formed in the mold. After that, the eject pin is lowered by the eject pin pushing means until the tip of the eject pin penetrates the blow tip and projects downward, and the molding sand in the blow hole and the blow tip is pushed to the filling port provided in the mold. After inserting the eject pin, the sand tank is raised with the tip of the eject pin protruding from the blow tip to separate the blow tip from the filling port in the mold. A gas supply chamber partitioned by the upper surface is formed. In this state, if a pressurized hardening gas is introduced into the gas supply chamber, the hardening gas is injected into the molding sand filled in the cavity through the filling port of the mold, and the molding sand is injected. Will be cured. Then, after the mold sand is opened after hardening of the foundry sand, the sand tank is lowered again with the tip of the eject pin protruding from the tip of the blow tip, and the blow tip is opposed to the foundry sand filling port in the mold. If contacted, the tip of the eject pin protruding from the blow tip will enter the filling port of the mold, and the cured molding sand, that is, the desired mold will be separated from the mold. Become.

In this way, the blowing process and the gassing process,
Furthermore, the ejecting process, without moving the mold,
It will be done at the same station. Moreover, during the gassing process, the tip end portion of the eject pin is projected from the blow tip, and the tip outer peripheral surface of the eject pin is configured to be in close contact with the inner peripheral surface of the blow tip. It will be surely prevented from flowing into the sand tank.

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

As shown in FIG. 1, a gas curing type mold making apparatus 11 according to this embodiment is supported by a frame 12 in a suspended manner,
Further, the lower surface 13 ′ has a sand tank 13 which is a blow head part which is in contact with the upper surface of the mold A installed below, and the sand tank 13 is lifted and lowered fixed to the lower surface of the frame 12. It is attached to the lower end portion of piston rods 15 ... 15 which project downward from the working cylinders 14 ... Further, a gassing case 16 suspended and fixed to the frame 12 is externally fitted to the outer side surface of the tank 13, and the tank 13 is vertically slidable with respect to the gassing case 16. . Further, in the center of the sand tank 13, a pipe 17 and a pipe 18 fitted therein are inserted from the upper surface to the vicinity of the bottom, and a space between the pipe 18 and the pipe 17 is formed in the tank. In order to introduce pressurized air from the pressurized air source (not shown) into the air passage 19 or the tank 13 at the upper end portion of the pipe 17 which projects from the upper surface of the tank 13 Is connected to the air supply pipe 20. Further, the inside of the pipe 18 is also a sand passage 21 which also communicates with the inside of the tank 13, and the upper end opening 18a of the pipe 18 is the frame 12
The hopper 2 is closed by a crimping valve 23 driven by a cylinder 22 fixed on the upper surface of the hopper 2 and is disposed on the frame 12 when the crimping valve 23 is retracted upward.
The foundry sand B stored in the No. 4 is introduced into the passage 21 or the tank 13 through the opening 18a via the foundry sand supply device 25. The foundry sand supply device 25
Is a gassing case 1 as shown in FIG.
6, a cylinder 27 fixedly supported on the upper side of 6 through a bracket 26, and a piston rod 2 in the cylinder 27.
Base 28 fixed to the tip of 7a, reciprocated and reciprocated, and slidably contacting the upper end opening 18a of the pipe 18, and a casting sand supply fixedly supported on the base 28 and formed at the side end of the base 28. And a cylinder 30 that drives a shutter 29 for opening and closing the mouth 28a,
As shown in the drawing, the cylinder 22 is driven to retract the crimping valve 23 upward, and then the cylinder 27 is driven to move the base 28 forward so that the supply port 28a in the base 28 and the upper end opening 18a in the pipe 18 are moved. After making them coincide with each other, by retracting the shutter 29 through the cylinder 30, the molding sand B stored in the hopper 24
Is introduced into the pipe 18 through the supply port 28a and the upper end opening 18a through the supply pipe 31 connected to the lower end of the hopper 24, whereby the sand tank 13
Foundry sand B is supplied into the interior.

However, the sand tank 13 is composed of an upper tank 13a whose lower surface is opened and a lower tank 13b whose upper surface is opened. The sand tank 13 is provided at the lower outer peripheral edge of the upper tank 13a and the upper outer peripheral edge of the lower tank 13b, respectively. By fastening the flange portions 13a 'and 13b' with suitable fastening members such as bolts (not shown), the quantity tank 1
Hollow sand tank 13 in which 3a and 13b are integrated
Is configured.

Further, inside the upper tank 13a, there is provided an extruding plate 32 in which an outer peripheral wall and an inner peripheral wall are fitted to the inner peripheral surface and the outer peripheral surface of the pipe 17 projecting into the tank 13a so as to be vertically slidable. In addition, the eject plate 32 is vertically moved through a piston rod 33 ... 33 between a position retracted upward as shown in FIG. 1 and a position below a certain stroke (see FIG. 2). Cylinders 34 ... 34 are installed.

On the other hand, in the lower tank 13b, a plurality of cylindrical bodies 35 ... 35 which are erected from the bottom thereof are arranged. 35a are formed in the lower side surface of the cylinders 35 ... 35, which are open to a plurality of blow holes 36 ... 36 provided on the lower surface 13 'of the sand tank 13, and the cylinders 35 ... Eject pins 37 ... 37 are pierced through the respective 35 so as to be vertically movable, and each eject pin 37
Is normally biased upward by a spring 37a mounted in the tubular body 35 and is normally held at the upper end position shown.
Then, at this time, the upper end portion of each eject pin 37 is located immediately below the push-out plate 32 at the upper position,
Further, the lower end portion is located so as to face the blow hole 36 from above.

Here, each of the cylinders 35 to the eject pin 37 is
It is provided on the upper wall of the die (upper die A ₁ ) so as to face the location of the filling ports A ″ ... A ″ of the molding sand B leading into the cavity A ′ and at the bottom of each blow hole 36. Blow chips 38 ... 38 having an inner hollow shape are attached to the periphery as shown in the drawing, and when the lower surface (blow head) 13 ′ of the sand tank 13 is brought close to the upper surface of the mold A, the blow chips 38. The blow holes 36 and the filling ports A ″ are communicated with each other in a state in which 38 is in contact with the filling ports A ″. In that case, the blow tip 38 seals the communication portion between the blow hole 36 and the filling port A ″, and as shown in FIG.
When the tip portion of 7 is fitted into the blow tip 38,
The inner diameter of the eject pin is set so that the inner peripheral surface of the blow tip 38 closely contacts the outer peripheral surface of the tip of the eject pin.

Also, as shown in FIG.
The cylinder 14 suspended on the lower surface of the frame 12 and the lower end surface of the gassing case 16 externally fitted to the outer surface of 3 are closely attached to the upper surface of the upper mold A ₁ forming the mold A. Sand tank 13 through piston rod 15
Of the blow tip 38 mounted around the lower portion of the blow hole 36 on the lower surface of the tank 13
Is separated from the filling port A ″ provided in the upper mold A ₁ by an upper side, the gassing case 16 is separated from the outer surface of the sand tank 13 and the upper surface of the upper mold A ₁ , and the filling port A ″ is separated. A gas supply chamber 39 communicating with the cavity A ′ is formed, and a supply pipe 40 for introducing a casting sand hardening gas into the gas supply chamber 39 is formed on the side of the gassing case 16. It is connected to the introduced inlet 16a.

As shown in FIG. 1, at the bottom of the lower mold A ₂ that constitutes the mold A, the hardening gas injected into the cavity A ′ during the gassing process is provided with a suction passage formed in the pedestal C. A discharge passage 42 for discharging to 41 is provided, and at the upper end of the passage 42, a vent plug 43 having an upper surface stretched with a net for preventing leakage of foundry sand is mounted.

Next, the operation of this embodiment will be described. First, as shown in FIG. 1, the cylinder 2 fixed to the upper surface of the frame 12
2 is driven to retract the crimping valve 23 above the upper end opening 18a of the pipe 18, and then the casting sand supply device 25 is used to knead in advance a kneading agent in the hopper 24 in a required amount of casting. Sand B to the upper end opening 18a of the pipe 18
Is supplied into the sand tank 13 from the
After closing the upper end opening 18a of the pipe 18 with
The sand tank 13 is lowered by the cylinder 14 suspended from the lower surface of the frame 12, and its lower surface 13 'is brought close to the upper surface of the mold A (upper mold A ₁ ) set below. At this time, the blow tip 38 mounted around the lower portion of the blow hole 36 formed on the lower surface of the sand tank 13 is
The molding sand filling port A ″ provided on the upper surface of the upper mold A ₁ is brought into contact with the upper mold A ₁ , so that the inside of the sand tank 13 and the cavity A ′ formed in the mold A are separated from each other by the holes 35 in the cylindrical body 35.
a, the blow hole 36, the blow tip 38, and the filling port A ″ of the upper mold A ₁ for communication.

Next, in this state, if pressurized air is introduced into the sand tank 13 through the air supply pipe 20 provided at the upper end of the pipe 17, the foundry sand B stored in the tank 13 will be described.
By the pressure of air, the holes 35a, the blow holes 36,
It is filled into the cavity A ′ of the mold A through the blow tip 38 and the filling port A ″. Thereafter, the upper tank 13a.
The cylinder 34 provided therein lowers the pressing plate 32 to lower the eject pin 37 until the tip of the eject pin 37 penetrates the blow tip 38 and projects downward, whereby the blow hole 36 and the casting in the blow tip 38 are cast. The sand B is pushed into the filling port A ″ of the upper mold A _1. Then, as shown in FIG. 2, the tip of the eject pin 37 remains protruding from the blow tip 38 and the sand tank 13
The cylinder 14 again to raise the blow tip 38
Is separated from the filling port A ″ of the mold A, a gas supply chamber 39 partitioned by the gas sink case 16 and the outer surface of the sand tank 13 and the upper surface of the upper mold A ₁ is formed. In this state, if the hardening gas pressurized is supplied into the gas supply chamber 39 through the inlet 16a, the hardening gas passes through the filling port A ″ of the upper mold A ₁ and into the cavity A ′. The foundry sand B is injected into the filled foundry sand B and hardened, whereby the core of the shape of the cavity A'is formed. At this time, since the outer peripheral surface of the eject pin 37 is intimately contacted with the inner peripheral surface of the blow tip 38, the both are surely sealed and the curing pin supplied into the gas supply chamber 39 is cured. Gas does not flow into the sand tank 13 from between the blow tip 38 and the eject pin 37.

When the core is formed in the mold A in this way, the supply of the curing gas into the gas supply chamber 39 is stopped, and then the pressurized air source is supplied via the supply pipe 40 and the inlet 16a. By supplying pressurized air to the gas supply chamber 39 (not shown), the mold A can be supplied not only in the gas supply chamber 39.
The curing gas filled in the cavity A'of
After being introduced into a neutralization tank (not shown) provided at a predetermined position through a discharge passage 42 provided in the lower mold A ₂ and a suction passage 41 formed in the pedestal C, it is shown in FIG. Clamping device D, D separately provided for the mold A
The die A of the mold A is opened by bringing the upper die A ₁ constituting the above into close contact with the lower end surface of the gassing case 16 and lowering the cradle C and the lower die A ₂ placed on the pedestal C. but at this time, the core is formed in the cavity a 'E is in a state bound to the lower upper mold a _1.

Then, in this state, the sand tank 13 is lowered by the cylinder 14 suspended from the lower surface of the frame 12 with the tip of the eject pin 37 protruding from the blow tip 38 as shown in FIG. When the blow tip 38 is again brought into contact with the filling port A ″ of the upper mold A _1, the eject pin 3 protruding from the blow tip 38 is ejected.
7 of the tip is to be plunged into the filling opening A "in the upper mold A _1. Thus, the core has been coupled to the upper mold A ₁ E is separated from the upper mold A _1, previously carried downward Receiving member F
It is taken out above.

In this way, a series of mold making operations are completed and the core E is molded. According to this apparatus 11, the mold A is
The blowing step of blowing the molding sand B into the cavity A'and the gassing step of injecting a hardening gas into the molding sand filled in the cavity A'to harden the molding sand B, as well as each of these steps. The ejecting process to be performed later can be performed at the same station.

Moreover, during the gassing process, the blow tip 38
Since the tip end of the eject pin 37 is projected into the inside and the tip outer peripheral surface of the eject pin 37 is in close contact with the inner peripheral surface of the blow tip 38, the curing gas does not flow into the sand tank 13. The unused molding sand B in the sand tank 13 is not hardened.

On the other hand, when the mold A is replaced to manufacture a different type of core, the blow hole 3 in the lower surface 13 ′ of the sand tank 13 is replaced.
6 ... 36 and the eject pin 37 arranged opposite thereto
.. 37 must be made to correspond to the positions of the respective molding sand blowing holes A ″ ... A ″ on the upper surface of the mold A to be newly used. In this case, in the device 11, the blow holes 36 ... 36 and the eject pins 37 ...
37 is provided in each of the divided lower tanks 13b of the sand tank 13, and each eject pin 3 is provided.
Since the pushing plate 32 for pushing 7 ... 37 and the cylinders 34 ... 34 for driving the pushing plate 32 are provided on the upper tank 13a side separately from the pins 37 ... 37, as described above, for example, a bolt (not shown). The lower tank 13b is removed by releasing the fastening between the upper tank 13a and the lower tank 13b by a suitable fastening member such as (4), and instead, a blow hole corresponding to a newly used mold is used. Further, it suffices to mount the lower tank in which the eject pins are arranged, and it is not necessary to replace the eject pin pushing plate 32 or the cylinders 34 ... 34. And even when using this new lower tank, during the gassing process and the eject process,
In the same manner as the above case, a plurality of eject pins mounted in a new lower tank can be simultaneously extruded by the extruding plate 32 and the cylinders 34 ...

As shown in an enlarged view in FIG. 5, a passage 44 'communicating with the hollow portion 38a' of the blow tip 38 'having an inner hollow shape is formed in the wall portion of the lower tank 13a ", and this passage is formed. For example, pressurized air may be supplied into the hollow portion 38a 'of the blow tip 38' via 44 'to increase the internal pressure of the hollow portion 38a'. By this action, the inner peripheral surface of the blow tip 38 'is pressed against the outer peripheral surface of the tip of the eject pin 37', and the sealing function between the two is further enhanced. Even when, for example, the inner peripheral surface of the blow tip 38 'is worn down due to repeated rushing of', the inner peripheral surface of the blow tip 38 'is constantly ejected by the action of the pressurized air. Supposed to be in close contact with the front end outer peripheral surface of Topin 37 ', the sealing function is never impaired therebetween.

(Effects of the Invention) As described above, according to the present invention, the effect 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 effect the molding sand. In a gas curing type mold making apparatus that is configured to cure and mold a mold, the gassing case is fitted on the outside of the sand tank so as to be vertically movable relative to the sand tank, and The eject pin is arranged facing the blow hole provided on the lower surface, and the eject pin is driven from the retracted position to the position where the tip of the eject pin projects below the blow tip mounted around the blow hole. Providing eject pin pushing means in the sand tank,
Furthermore, since the inner peripheral surface of the blow tip is configured to be in close contact with the outer peripheral surface of the eject pin when the tip of the eject pin is inserted into the blow tip, a blowing step of blowing molding sand into the mold from the blow hole. In addition to performing the gassing step of injecting a hardening gas into the molding sand filled in the mold to cure the molding sand, the eject step of removing the product from the mold with the above eject pin should be performed at the same station. This makes it unnecessary to move the mold between the gassing process and the ejecting process as in the prior art, which shortens the cycle time of this type of molding work and reduces the size of the molding apparatus. It will be possible. And, especially when exchanging the mold for manufacturing different kinds of products, it is sufficient to replace only the lower tank provided with the eject pin facing the blow hole. The work time will be shortened.

Further, at the time of the gassing step, the tip of the eject pin is projected into the blow tip, and the inner peripheral surface of the blow tip is in close contact with the outer peripheral surface of the tip of the eject pin. As a result, the hardening gas is prevented from flowing into the sand tank from between the blow tip and the eject pin, and the unused foundry sand in the sand tank is not hardened. Therefore, there is no possibility of impeding the subsequent blowing process.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view showing a state of the gas curing type mold making apparatus according to the present embodiment during a blowing step, and FIG. 2 is a diagram showing a state of the gas curing type mold making apparatus during a gassing step. 3 is an enlarged cross-sectional view of a part, FIG. 3 is an enlarged cross-sectional view of a main part showing a state during an ejecting process, FIG. FIG. 6 is an enlarged cross-sectional view showing another embodiment of the blow tip mounted on the, and FIG. 6 is a vertical cross-sectional view showing a conventional mold making machine. 13 ... Sand tank, 16 ... Gassing case, 3
2 ...... extruded plates, 36 ...... blow hole, 37 ...... eject pin, 38 ...... blow chips, A ...... mold (upper mold _{A 1,} lower mold _A 2), A '...... cavity, A "... … Casting sand filling port, B… Casting sand.

Claims (1)

[Claims] 1. A molding sand filled in a sand tank is filled in a mold through a blow hole provided on a lower surface of the tank, and a hardening gas is injected into the molding sand in the mold. A gas hardening type mold making apparatus for molding a mold by hardening the molding sand, which is installed around a blow hole provided on the lower surface of the sand tank and provided on the upper surface of the mold. The blow tip made of an elastic material that is in contact with the foundry sand filling port is fitted to the outside of the sand tank so as to be vertically movable relative to the same, and the lower end surface faces the upper surface of the mold. A gassing case that forms a gas supply chamber that communicates with the cavity formed in the mold through the filling port when the blow tip is separated from the filling port in the mold in a contact state; Under the sand tank An eject pin which is disposed so as to oppose the blow hole provided in the blow tip and whose outer peripheral surface is in close contact with the inner peripheral surface of the blow tip when the tip is thrust into the blow tip; A gas hardening type mold making apparatus, characterized in that it is provided with an eject pin pushing means for driving a tip portion thereof to a position where it penetrates the blow tip and projects downward.