JPS608903B2 - Core support device for castings - Google Patents

Description

[Detailed description of the invention] The present invention relates to a foundry core support device.

Conventionally, for example, in order to form a cutter holder □ in centrifugal casting of a tube, a cauldron part 2 is formed on the inner surface of one end of a cylindrical rotating metal frame 1, and a ring-shaped sand mold is formed inside the cauldron part 2, as shown in Fig. 1. The core 3 is supported by a front cover 5 which is attached to the inner periphery of one end of the rotary metal frame 1 with a knock pin 4 or the like using an outer iron.

However, because the core 3 is compacted between the casting tube P and the front lid 5 due to solidification shrinkage of the molten metal, it is extremely difficult and time-consuming to remove the front lid 5 from the inner periphery of the core 3 after casting is complete. This was time consuming and was an impediment to improving casting efficiency. Therefore, as shown in FIG. 2, the present applicant previously installed an annular slide member 7 on the outer periphery of the cylindrical portion 6 where the core 3 of 5 is placed on the outside where the core 3 is most compacted. The front cover 5 formed as a result of the relative sliding between the slide member 7 and the front cover 5 during the early stage of extraction reduces the influence of compaction of the core and facilitates extraction.
We have proposed a method in which the sand in the core 3 that has been compacted into the space between the core 3 and the core 3 is released so that it can be easily extracted afterwards, but it still requires a fairly large extraction force. Furthermore, there was a desire for a front lid that could be pulled out even with an extraction force of 4.0 mm. In view of such demands, it is an object of the present invention to provide a casting core support device that can extract the core from the inner periphery with an extremely small extraction force.

The support device of the present invention fixes the annular support frame to one end of the rotary metal frame using a knock pin, and has a tapered outer peripheral surface that expands in three directions on one side of the chest D, and has a tapered outer peripheral surface that expands in three directions on one side of the chest D. An annular operating cylinder having a cylindrical part that can be moved inward in the axial direction is provided on the inner periphery of the annular support frame, and the outer peripheral surface is iron-fitted to the inner peripheral surface of the annular core, and the taper The inner circumferential surface of the Chinapa attached to the outer circumferential surface is formed and has a shrinking force at one location in the circumferential direction, and this shrinking force causes the operating cylinder to move relatively in one direction of the axis 0. A ring is provided, and the divided end faces of the divided parts of the retaining ring are tilted in an open (V-shaped) shape toward one direction of the self-axis, and have a triangular planar shape and fit between the divided end faces, and the outer surface is arranged in the direction of the core. An auxiliary block formed on a cylindrical surface with a diameter slightly smaller than the inner circumferential surface of the cylinder is mounted on the tapered outer circumferential surface of the operating cylinder, and a stopper block is installed at the end of the operating cylinder on the other side of the axis to prevent the retaining ring from slipping out. In addition to fixing the retaining ring, the retaining ring includes a shoulder that engages with the retaining ring, and a shoulder that extends from the shoulder toward the outside of the outer periphery of the retaining ring to support the core portion at a position corresponding to the retaining ring. a first recess that avoids the operating cylinder on the inner surface of the annular support frame, and a second recess that avoids the core on the outer surface of the retaining ring; An elliptical connecting ring that prevents displacement of the holding ring in the axial direction is hung between a pair of locking pins provided in both recesses, and the operating cylinder is axially centered relative to the annular support frame. A push bolt is provided that expands the retaining ring by relatively moving in the other direction and presses the outer circumferential surface of the retaining ring against the inner circumferential surface of the core. When the core is held and casting is completed, the push bolt is loosened and the operating cylinder is moved in one direction of the axis by the shrinking force of the retaining ring, thereby warping the retaining ring and aligning it with the inner periphery of the core. A gap is created between them, allowing the support device to be pulled out without any resistance.

Hereinafter, a third embodiment of the present invention in which the present invention is applied to a front lid for centrifugal casting will be described.
This will be explained with reference to FIGS. 11 to 11.

FIG. 3 is a sectional view showing the front cover 10 in a state where the core is not supported, and FIG. 4 is a sectional view showing the front cover 10 in a state where the core is supported. With one side of the outer periphery in contact with the formed front cover mounting shoulder 8, an annular support is fixed to the rotating metal frame 1 using knock pins similar to those shown in FIGS. 1 and 2, although not shown. The rotary metal frame 1 is a frame, and an annular recess 12 is formed in the inner circumferential portion of the rotary metal frame 1, which extends radially inward from the inner circumference of the core 3 and is open to the back side and the radially inner side of the rotary metal frame 1. Reference numeral 13 denotes an operation cylinder having a tapered outer circumferential surface 14, one end of which is formed into a cylindrical portion 15 that is continuous with the green side end of the tapered outer circumferential surface 14, and is slidable on the circumferential surface of the annular recess 12. It has been made possible to do so.

An annular support frame 11 forms a side surface of the annular recess 12.
Push bolts 17 are screwed into the flange 16 that protrudes from the inner circumference at multiple locations in the circumferential direction and penetrate in the axial direction, and the tips of the push bolts 17 are in contact with one end surface 13a of the operation cylinder 13. I'm right. Further, a key groove 18 in the axial direction is formed at a suitable position in the circumferential direction of the circumferential surface of the annular recess 12 as shown in FIG. A key 19 is attached thereto, and the operating barrel 13 is configured to slide smoothly along the axis without rotating. 20
5 is a retaining bolt placed at the end of the keyway 18.

Reference numeral 21 denotes a retaining ring whose outer periphery is iron-coupled with the inner periphery of the core 3, and as shown in FIG. 14 is formed with a tapered inner circumferential surface 22 that is slidably curved outward.

As shown in FIG. 4, the retaining ring 21 and the annular support frame 11 are connected to each other by connecting rings 23 at two diametrically opposed locations separated by 9 pips from the divided portion of the retaining ring 21. Z are connected to each other in a state that allows radial displacement due to the diameter. That is, as shown in FIGS. 6 to 8, a recess 24 capable of accommodating a part of the connecting ring 23 is provided on the circumferential surface of the annular recess 12 of the annular support frame 11, and a screw hole 2 in the bottom surface of the recess 24 is provided.
A locking pin 26 is screwed into the retaining ring 21, and a recess 27 is provided on the outer periphery of the retaining ring 21 to accommodate the remaining part of the connecting ring 23. An oblong connecting ring 23 as shown in FIG. 8 is hung between these locking pins 26 and 29. 30 is the connecting ring 23
It is a plate material for length adjustment.

With the annular support frame 11 and the retaining ring 21 connected in this way, push the operation cylinder 13 toward the other end and push the bolt 17
By sliding the holding ring 21, the tapered outer circumferential surface 14 of the operating cylinder 13 widens the holding ring 21, but the opposing split ends 31a and 31b of the holding ring 21 are therefore separated, and the middle I will no longer be able to support child 3. Therefore, as shown in FIGS. 5 and 9 to 11, these divided end surfaces 31a
, 31b are inclined in a V-shape so as to open toward the remaining side of the tapered inner circumferential surface 22, and the tapered outer circumferential surface 1 of the operating cylinder 13 is
Attached to 4 is an auxiliary block 33 having a substantially triangular planar shape with a pair of slopes facing the divided end surfaces 31a and 31b, and a cylindrical surface whose outer periphery is slightly smaller than the inner peripheral surface of the core 3. . The angle of inclination of the tapered outer circumferential surface 14 is set to be larger than the friction angle between the operating cylinder 13 and the holding ring 21, and the holding ring 2 releases the pressure from the push bolt 17.
The operation cylinder 13 is slid toward one end thereof by the elastic diameter reduction urging force of 1, and the retaining ring 21 is configured to have a vertical diameter. The inclination angle of the operating cylinder 13 and the retaining ring 21 is
the relative sliding distance of and the divided end surface 31a corresponding to the sliding distance.
, 31b is set at an angle such that the ratio of half of the distance between the retaining rings 21 and 31b is a sine, so that even if the retaining ring 21 is fully expanded, no gap is created between the divided end surfaces 31a, 31b and the auxiliary block 33. I'm doing it like that. In this way, as shown in FIGS. 3 and 9, the outer diameter of the retaining ring 21 is considerably smaller than the inner diameter of the core 3, and the minimum gap between the divided end surfaces 31a and 31b is q, When the operation cylinder 13 is moved as shown by the arrow in FIG. 9a, the outer diameter of the retaining ring 21 becomes Do + ΔD as shown in FIG. 10. On the other hand, along with this, the split end face 30
The minimum gap between a and 30b is Δd, but the auxiliary block 33 penetrates deeper between the divided end surfaces 30a and 30b, and a gap is created between the divided end surfaces 31a and 31b and both slopes of the auxiliary block 33. do not have. Furthermore, when the operation cylinder 13 is moved as shown by the arrow in FIG. 10a,
As shown in the figure, the outer diameter of the retaining ring 21 is a diameter D equal to the inner diameter of the core 3, so that the core 3 is supported side by side, and the gap between the divided end surfaces 31a and 31b of the retaining ring 21 is the same as the inner diameter of the core 3. Since the core 3 is filled without creating any gaps, there is no place where the core 3 would be lifted up while being supported. In addition, numeral 32 in the figure is a stop ring fixed to the other end of the operation cylinder 13 to prevent the retaining ring 21 from coming off, and can be engaged with a shoulder 34 on the inner circumference of the retaining ring 21. It has an extension tube part 35 extending in a cylindrical shape from the shoulder part 34 so as to be able to support the entire length of the shoulder part 34. In the above configuration, in order to support the core 3 with the front cover 10, the retaining ring 21 is attached as shown in FIG.
When the core 3 is placed on the outer periphery of the cylinder and the push bolt 17 is then operated to move the operation cylinder 13 toward the other end, it operates as shown in FIGS. 9 to 11 as described above. Middle child 3
is externally supported by the retaining ring 21.

Next, the front cover 10 with the core 3 attached is fixed to the inner periphery of one end of the rotating metal frame 1 with a knock pin (not shown) as shown in FIG. By pouring molten metal, a pipe body P having a receiving □ inner circumference corresponding to the core 3 is formed.
is centrifugally cast. When the tube P solidifies and casting is completed, the front cover 10 is pulled out from the rotating metal frame 1 and the inner periphery of the core 3, but due to the solidification and contraction of the tube P, the core 3 is removed from the tube P.
and the retaining ring 21, and the retaining ring 21 and the core 3 are strongly pressed together. However, in this front cover 101, when the push bolt 17 is loosened so that the operation cylinder 13 can be moved to one end side, the retaining ring 21 is moved as shown in FIG.
The operation cylinder 13 moves to one end side due to the total flea urging force, and the diameter of the holding trench 21 is reduced to create a gap between its outer periphery and the inner periphery of the core 3. Thus, the front cover 10 can be removed very easily. It can be pulled out. According to the casting core support device of the present invention,
As is clear from the above explanation, by moving the operation cylinder after casting is completed, the diameter of the retaining ring that supports the core can be reduced, so that the core is compressed by solidification contraction of the cast product. The support device can be pulled out extremely easily even if the support device is
Significantly improves the overall productivity of casting.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a conventional front cover for far-D casting, and FIGS. 3 to 11 show an embodiment in which the present invention is applied to a front cover for far-D casting. Fig. 4 is a cross-sectional view of the core with the core attached, Fig. 5 is a perspective view showing the schematic structure of the operating cylinder and the retaining ring, and Fig. 6 is a cross-sectional view of the core without the core attached. The annular support frame is shown, a is a cross-sectional view, b is a bottom view of a, and the seventh
The figure shows the retaining ring, a is a partial plan view, b is a sectional view, and
The figures show a connecting ring, in which a is a plan view, b is a sectional view, and FIGS. 9 to 11 are explanatory diagrams showing operating states, where a is a sectional view and b is a plan view. 10... Front lid, 11... Annular support frame, 12
. . . Annular recess, 13 . . . Operation cylinder, 14.
・...Outer circumferential surface of the tab, 17... Push bolt, 2
1...Retaining ring, 22...Narper inner peripheral surface, 23...Connection ring, 31a, 31b...Divided end surface, 33...Auxiliary block. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] 1. An annular support frame is fixed to one end of the rotary metal frame using a dowel pin, and has a tapered outer circumferential surface that expands in diameter toward one direction of the axis, and an inner circumference of the annular support frame in one direction of the axis. An annular operating cylinder having a cylindrical portion that is slidably fitted in the axial direction is provided, the outer circumferential surface of which fits into the inner circumferential surface of the annular core, and a taper which fits externally into the tapered outer circumferential surface. A retaining ring is provided, which has an inner circumferential surface and has a diameter reduction biasing force at one location in the circumferential direction, and uses this diameter reduction biasing force to move the operating cylinder relatively in one direction of the axis. A cylinder whose divided end surfaces in the divided portion are inclined in a V-shape that opens toward one direction of the axis, and which has a triangular planar shape and fits between the divided end surfaces, and whose outer surface has a slightly smaller diameter than the inner circumferential surface of the core. An auxiliary block formed on a surface is attached to the tapered outer circumferential surface of the operating cylinder, and a retaining ring for preventing the retaining ring from slipping out is fixed to the end on the other side of the axis of the operating cylinder, and the retaining ring includes: A shoulder portion that engages with the retaining ring, and an extended cylindrical portion extending from the shoulder portion toward the outside of the outer periphery of the retaining ring to support the core portion at a position corresponding to the retaining ring, and A first recess is formed on the inner surface of the support frame, avoiding the operating cylinder, and a second recess is formed on the outer surface of the retaining ring, avoiding the core. An elliptical connecting ring that prevents displacement of the holding ring in the axial direction is hung between the stop pins, and the holding ring is moved by moving the operation cylinder relative to the annular support frame in the other direction of the axis. A casting core support device for castings, characterized in that a press bolt is provided for expanding the diameter of the ring and pressing the outer circumferential surface of the retaining ring against the inner circumferential surface of the core.