JP4685358B2 - Wire mesh filter for casting machine - Google Patents

Description

  The present invention relates to a wire mesh filter for a casting machine to be installed in a gate of a casting machine for low pressure casting.

  Conventionally, for example, a cylinder head of a motorcycle engine is cast by a low pressure casting method. As a casting machine for low pressure casting, for example, there is one disclosed in Patent Document 1. In the casting machine shown in Patent Document 1, a crucible is arranged below a mold composed of a lower mold and an upper mold, and the molten metal stored in the crucible is pressurized to pass through a stalk and a gate cup. The structure which pushes up and supplies to the gate of the said lower mold is taken.

In order to prevent the oxide generated in the crucible and the stalk and foreign matter in the molten metal from flowing into the mold together with the molten metal, this type of casting machine is made of a metal mesh in the gate as shown in FIG. The filter is installed.
FIG. 5 is an enlarged cross-sectional view of a sprue portion of a casting machine equipped with a conventional filter. In FIG. 5, reference numeral 1 denotes a lower mold, 2 denotes a lower mold support member, and 3 denotes a spout cup. Reference numeral 4 denotes a filter, and 5 denotes a molten metal solidified in the mold.

  The lower mold 1 is formed so that the cavity 6 opens upward, and is fixed to a base (not shown) via the lower mold support member 2. The cavity 6 is formed by a lower mold and an upper mold (not shown), and a runner 7 is formed at the lower end. The runner 7 is formed in the lower mold 1 so as to be recessed below the product portion 8 indicated by a two-dot chain line in the figure, and a gate 9 is opened on the bottom surface thereof.

  The gate 9 is connected to a gate cup 3 held by the lower mold support member 2. Although not shown, the pouring cup 3 has a stalk connected to the lower end portion thereof and communicated with the crucible through the stalk. That is, in this casting machine, the molten metal is pushed up to the pouring cup 3 through the stalk, and supplied from the pouring cup 3 through the pouring gate 9 into the cavity 6 (runner 7).

  The said gate 9 is formed so that an opening diameter may become large gradually as it goes upwards, and the filter 4 is mounted | worn at the intermediate part. The filter 4 is made of a wire mesh formed into a cylindrical shape with a bottom by pressure molding, and is fitted with the gate 9 so as to extend in the vertical direction, and a vertically extending portion 4a, and an upper end of the vertically extending portion 4a. A disc-shaped filter main body 4b provided so as to partition the gate 9 in the vertical direction is formed integrally with the portion. The filter 4 is inserted into the gate 9 from the cavity 6 side, and is pressed into the gate 9 while being elastically deformed by being pushed by an operator.

In this conventional casting machine, when the molten metal is supplied into the cavity 6 through the filter 4 and the molten metal fills the cavity 6 and solidifies in the vicinity of the pouring gate 9, pressurization of the molten metal on the crucible side is stopped. . By stopping the pressurization in this way, the unsolidified portion of the molten metal flows down to the crucible, and the solidified portion (molten metal 5) remains on the mold side. In the conventional casting machine, the pressurization time is set so that the filter 4 enters the solidified portion and is in a cast-in state (see FIG. 5). For this reason, the filter 4 is removed from the gate 9 together with the casting by releasing the casting upward from the lower mold 1 after casting.
In addition, the applicant could not find any prior art documents closely related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in the present specification. .
Japanese Patent Laid-Open No. 11-57979

  In the conventional casting machine configured as described above, the filter 4 is attached to the gate 9 by an operator, and the force when the filter 4 is press-fitted into the gate 9 varies depending on the operator. There was a risk that it could be installed in an appropriate position. For example, when the filter 4 is mounted at a position relatively close to the runner 7 (upper side in the drawing), the force for fixing the filter 4 in the gate 9 becomes small, so that the filter 4 is pushed by the molten metal during casting. As a result, the runner 7 may come off from the gate 9 and enter the product portion 8. If the filter 4 enters the product portion 8 in this way, the cast product becomes a defective product.

On the other hand, when the filter 4 is mounted at a position relatively close to the gate cup 3 (downward in the figure), the filter 4 may not be able to be taken into the solidified portion 5 of the molten metal. In this case, since the remaining casting material to the filter 4 is a sprue 9 also be releasing, must come remove the filter 4 to stop the casting machine before performing subsequent casting, continuous operation of the casting machine Can no longer do. In order to prevent such a situation from occurring, conventionally, the molten metal is pressurized until the solidified portion 5 of the molten metal reaches the lower part of the gate 9 so that the filter 4 does not remain in the gate 9. For this reason, there existed a problem that time (cycle time) required for one casting will become long.

  The present invention has been made to solve such problems, and does not come off from the gate due to the pressure of the molten metal, and the casting machine in which the filter is taken into the casting even if the pressurizing time of the molten metal is short. An object is to provide a wire mesh filter.

To achieve this object, the wire mesh filter for a casting machine according to the present invention is fitted and fitted from the runner side into a tapered gate whose opening diameter gradually increases toward the upper side of the casting machine for low pressure casting. A wire mesh filter for a casting machine, a filter main body having a cap shape with a collar having a flange formed on the entire lower periphery of an upper convex cap body , and a lower portion extending downward from the outer periphery of the filter main body An annular recess is formed between the outer periphery of the collar and the cap body, and the outer periphery of the collar has an annular protrusion on the outer periphery of the collar. As it is formed, it is curved so as to be positioned downward as it goes outward in the radial direction, and is connected to the upper end portion of the downwardly extending portion, and the collar portion is the annular portion positioned on the inner peripheral side. The concave portion and the annular ring located on the outer peripheral side. By the Department formed in S-shaped cross-section, the lower extending portion are formed to be inclined along the tapered surface of the sprue, the cap body portion are those which projects into the runner.

A metal mesh filter for a casting machine according to a second aspect of the present invention is the wire mesh filter for a casting machine according to the first aspect of the present invention , wherein the outer diameter of the flange portion of the filter body is on the runner side of the gate. It is formed slightly larger than the inner diameter of the opening edge.

According to the present invention, since the filter body having the bent portion functions as a spring that can be elastically deformed substantially in the radial direction, the elasticity that presses against the peripheral wall of the gate is increased while the filter body is pushed into the gate. Can be made.
For this reason, since the filter can be firmly held in the gate, it is possible to reliably prevent the filter from coming off from the gate due to the pressure of the molten metal during casting, and the yield can be improved.

  In addition, since the cap body portion of the filter body protrudes upward from the collar portion that fits into the gate, the upper end portion of the cap body portion can be moved even when the filter body is positioned relatively below the gate. It can face the solidified part of the molten metal. For this reason, since a part of the filter (cap body) is in the solidified portion without waiting for the molten metal to solidify to the lower part of the gate, the time (cycle time) required for performing casting once is reduced. It can be shortened. In addition, since the filter can be reliably removed from the mold together with the casting, the casting machine is not stopped exclusively for removing the filter from the mold. Therefore, the productivity can be further improved in combination with the reduction of the cycle time as described above.

  According to the second aspect of the present invention, since the filter body can be positioned on the runner side opening edge of the gate with reference to the collar portion of the filter body, the filter can be installed even if the operator who installs the filter changes. The filter body can always be positioned at a fixed position so that the cap body of the body faces the runner. For this reason, since the pressurization of the molten metal can be stopped when the molten metal is solidified in the runner, the addition of the molten metal is compared to the case where the pressurization of the molten metal is stopped after the solidified portion of the molten metal reaches the pouring gate. The time to stop the pressure can be advanced. As a result, the cycle time can be further shortened, and the production efficiency can be improved.

Hereinafter, an embodiment of a wire mesh filter for a casting machine according to the present invention will be described in detail with reference to FIGS.
1 is a cross-sectional view of a low-pressure casting machine equipped with a filter according to the present invention, FIG. 2 is a plan view of a lower mold, FIG. 3 is a cross-sectional view showing an enlarged main part, and FIG. 4 is a perspective view of the filter. It is.
In these drawings, what is indicated by reference numeral 11 is a low-pressure casting machine according to this embodiment. This casting machine 11 is for casting a cylinder head (not shown) of a motorcycle engine by low pressure casting. As is well known in the art, a mold 13 is arranged on a furnace body 12. It is installed.

  The furnace body 12 includes a main body 14 formed in a box shape that opens upward, a lid body 15 that closes an upper opening portion of the main body 14, a crucible 17 that stores a molten metal 16, and the lid body 15. The stalk 18 etc. which were attached to the lower end part and were immersed in the molten metal 16 were comprised. The main body 14 of the furnace body 12 incorporates a heater (not shown) for heating the molten metal 16 in the crucible 17 to a predetermined temperature, and is connected to a pressurizing device (not shown). . This pressurizing device is for supplying an inert gas into the main body 14 at the time of casting, pressurizing the upper surface of the molten metal 16 and pushing the molten metal 16 into the stalk 18, and a connection port 14 a formed in the main body 14. A gas pipe (not shown) is connected to the.

The casting by the casting machine 11 is performed by pressurizing the inside of the main body 14 of the furnace body 12 with a pressurizing device in a state in which the mold 13 is clamped as in the conventional casting machine. The molten metal 16 is raised in the stalk 18 from the crucible 17 by being pressurized in the main body 14 during casting, and is supplied into the mold 13 positioned above.
The mold 13 includes an upper mold 21 and a lower mold 22 and is supported by a driving device 23. The upper mold 21 is formed with a cavity 24 that opens downward, and is attached to a platen 25 of a driving device 23. The platen 25 is supported on the base 26 of the driving device 23 through a tie bar 27 so as to be movable up and down, and is moved up and down by a lifting motor (not shown).

The lower mold 22 has a cavity 28 that opens upward, and is fixed on the base 26 by a support member 29. The lower mold 22 and the upper mold 21 include a heater (not shown) for preheating them to a casting temperature, and a water-cooled cooling device (not shown) for keeping the mold temperature constant during casting. )).
As shown in FIGS. 2 and 3, a runner 30 is formed on the bottom of the cavity 28 of the lower mold 22 so as to extend from one side of the cavity 28 to the other side, and from the bottom of the runner 30. A gate 31 is formed so as to extend downward.

  As shown in FIG. 2, the gate 31 is formed in an elliptical shape when viewed from above on the bottom of the lower mold 22, and as shown in FIG. 3, the opening diameter gradually increases toward the upper side to form a draft. It is drilled to do. A filter 32 (described later) is attached to the opening at the upper end of the gate 31, and the upper end of the gate 33 provided on the lower mold support member 29 is connected to the lower end of the gate 31. . As shown in FIG. 1, the gate cup 33 penetrates the support member 29 in the vertical direction, and the molten metal 16 is supplied from the upper end portion of the stalk 18 in contact with the lower surface of the support member 29. . That is, at the time of casting, the molten metal 16 flows from the stalk 18 through the gate cup 33 into the gate 31, passes through the filter 32 from the gate 31, flows into the runner 30, and is further supplied into the cavities 24 and 28. The

  The molten metal 16 filling the cavities 24 and 28 begins to solidify from the product portion 34 (see FIG. 3) in the cavities 24 and 28. The solidified portion of the molten metal 16 advances from the runner 30 into the gate 31 with time. The casting machine 11 according to this embodiment stops the pressurization by the pressurizing device when the solidified part has advanced to the vicinity of the boundary between the runner 30 and the gate 31 and causes the molten metal 16 in the unsolidified part to flow down to the crucible 17. . In this embodiment, the timing for stopping the pressurization is determined based on the temperature of the molten metal 16 in the vicinity of the boundary detected by a temperature sensor (not shown) attached to the lower mold 22. .

  As shown in FIGS. 3 and 4, the filter 32 includes a filter main body 35 having a cap shape with a collar, and a downward extending portion 36 extending downward from the outer peripheral portion of the filter main body 35. The filter 32 according to this embodiment is manufactured by molding a galvanized iron wire mesh by a pressure molding device (not shown). In FIG. 4, many auxiliary lines are drawn so that the shape of the filter 32 can be easily understood. The mesh of the filter 32 is formed by a wire mesh knitted in a direction different from the auxiliary line. .

The filter body 35 is formed in a bottomed cylindrical shape with a cap body portion 37 protruding upward, and a collar portion 38 is formed in a series without interruption in the entire lower periphery of the cap body portion 37. The collar portion 38 is formed with an annular recess 39 that opens upward between an outer peripheral edge 38 a connected to the downward extending portion 36 and the cap body portion 37. In this embodiment, the outer peripheral edge 38 a of the collar portion 38 is curved so as to be positioned gradually downward toward the outer side in the radial direction, and is smoothly connected to the upper end portion of the downward extending portion 36. . Thus, since the outer peripheral edge 38a of the collar portion 38 is curved and the annular recess 39 is located on the inner side in the radial direction from the outer peripheral edge 38a, the collar portion 38 is annularly located on the inner peripheral side. The recess 39 and the annular protrusion 40 located on the outer peripheral side are formed in an S-shaped cross section. The outer diameter of the collar portion 38 is formed to be slightly larger than the inner diameter of the runner side opening edge portion of the gate 31.
The downwardly extending portions 36 are portions corresponding to the four corners of the wire mesh before the filter 32 is formed by pressure molding, and extend downward from four locations on the outer peripheral portion of the filter main body 35. As shown in FIG. 3, the downwardly extending portion 36 is formed so as to be inclined along the tapered surface of the gate 31.

  As shown in FIG. 3, the filter 32 configured as described above has an outer peripheral edge of the flange portion 38 of the filter main body 35 at the runner side opening edge (downstream end portion) of the gate 31 when being press-fitted into the gate 31. It is attached to the gate 31 by press-fitting so as to be positioned. The press fitting of the filter 32 into the gate 31 is performed for each casting operation by an operator. The press-fitting operation is performed by inserting the lower extension 36 of the filter 32 into the gate 31 from the cavity 28 side of the lower mold 22, and the filter body 35 with the entire outer peripheral edge 38 a in contact with the peripheral wall of the gate 31. This is done by pressing into the gate 31. By pressing the filter body 35 downward in this manner, the annular recess 39 and the annular projection 40 constituting the collar portion 38 and the base end portion of the cap body portion 37 are elastically deformed, and the filter body 35 is Compressed radially. That is, the filter main body 35 having a bent portion functions as a spring that can be elastically deformed substantially in the radial direction.

Therefore, when the filter body 35 is pushed into the gate 31, the filter body 35 is pushed against the peripheral wall of the gate 31 by its own elasticity, so that the filter 32 can be firmly held in the gate 31. The elastic force is remarkably increased as compared with a conventional filter without the annular concave portion 39 or the annular convex portion 40.
The filter 32 according to this embodiment is pressed upward by the passage of the molten metal 16 at the time of casting. However, as described above, the filter 32 is pressed against the peripheral wall of the gate 31 by a larger elastic force than before. Even if the oxides and foreign matters are collected in the filter 32 and the pressing force acting on the filter 32 is increased, the oxide or foreign matter does not come out of the gate 31 and enter the product portion 34.

Further, since the cap body portion 37 of the filter body 35 protrudes upward from the collar portion 38 that fits into the gate 31, even if the filter body 35 is pushed down to the lower portion of the gate 31, The upper end portion enters the solidified portion of the molten metal 16. For this reason, since the cap body part 37 is in the solidified part without waiting for the pressurization to stop until the molten metal 16 solidifies to the lower part of the gate 31, the time required for carrying out the casting once (cycle time) ) Can be shortened. For this reason, conventionally, it has been necessary to continue pressurization of the molten metal 16 until the solidified portion expands to the position indicated by the two-dot chain line A in FIG. 3, but according to the casting machine 11 according to this embodiment, Pressurization could be stopped several tens of seconds earlier than before.

  Further, since the cap body portion 37 projects upward and enters the solidified portion of the molten metal 16, the filter 32 can be reliably removed from the mold 13 together with the casting. That is, since the casting machine 11 is not stopped only to remove the filter 32 from the mold 13, the productivity can be further improved in combination with the cycle time being shortened as described above. .

The filter main body 35 of the filter 32 according to this embodiment is press-fitted so that the outer peripheral edge 38 a of the collar portion 38 is positioned substantially at the runner side opening edge of the gate 31 when being pressed into the gate 31. In mounting, the filter body 35 can be positioned on the runner side opening edge of the gate 31 with the collar portion 38 as a guide. For this reason, even if the operator who wears the filter 32 changes, the filter body 35 can always be positioned at a fixed position so that the cap body 37 of the filter body 35 faces the runner 30.
Therefore, since the pressurization of the molten metal 16 can be stopped when the molten metal 16 is solidified in the runner 30, compared with the case where the pressurization of the molten metal 16 is stopped after the solidified portion of the molten metal 16 reaches the pouring gate 31. Thus, pressurization of the molten metal 16 can be stopped early. As a result, the cycle time can be further shortened, and the production efficiency can be improved.

It is sectional drawing of the casting machine for low pressure casting equipped with the filter which concerns on this invention. It is a top view of a lower mold. It is sectional drawing which expands and shows a principal part. It is a perspective view of a filter. It is sectional drawing which expands and shows the gate part of the casting machine with which the conventional filter was mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Casting machine, 13 ... Die, 21 ... Upper die, 22 ... Lower die, 24, 28 ... Cavity, 30 ... Runner, 31 ... Spout, 32 ... Filter, 35 ... Filter body, 36 ... Extending downward Part, 37 ... cap body part, 38 ... collar part, 39 ... annular concave part, 40 ... annular convex part.

Claims (2)

A wire mesh filter for a casting machine to be fitted and attached from the runner side into a tapered gate whose opening diameter gradually increases toward the upper side of the casting machine for low pressure casting,
A filter body presenting a hat-like shape with a collar having a collar formed on the entire circumference of the lower part of the upper convex cap body;
Consists of a downward extending portion extending downward from the outer periphery of the filter body,
An annular recess is formed between the outer periphery of the collar and the cap body,
The outer peripheral edge of the collar portion is curved so as to be gradually positioned downward toward the outer side in the radial direction so that an annular convex portion is formed on the outer peripheral side of the collar portion, and Connected to the upper end,
The collar portion is formed in an S-shaped cross section by the annular concave portion located on the inner peripheral side and the annular convex portion located on the outer peripheral side,
The downward extending portion is formed so as to be inclined along the tapered surface of the gate,
The cap body part protrudes into the runner, and is a wire mesh filter for a casting machine. The wire mesh filter for a casting machine according to claim 1 ,
A filter made of a wire mesh for a casting machine, wherein an outer diameter of a collar portion of the filter main body is formed slightly larger than an inner diameter of a runner side opening edge portion of the gate.

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