JPH10272540A - Method and apparatus for pre-compressing molding sand - Google Patents

Abstract

(57) [PROBLEMS] To pre-compress molding sand near the inner surface of a casting frame by a thin annular member against molding sand put into a space defined by a pattern plate and a molding frame. It is an object to provide a method and an apparatus for pre-compressing without damaging. SOLUTION: For a molding sand S put into a space defined by a pattern plate 4 and a casting flask 5, a tubular thin plate annular body 10 slightly smaller than the inner surface of the casting flask 5 is formed according to the pattern plate 4. And a method of pre-compressing the molding sand which is relatively inserted from above the molding sand S toward the pattern plate 4 until the insertion depth dimension or the insertion load value of the thin annular body 10 into the molding sand S is set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding sand which has been pre-compressed in the vicinity of an inner surface of a molding flask after the molding sand introduced into a space defined by a pattern plate and a molding flask. The present invention relates to a method and an apparatus for pre-compressing molding sand in a mold for pressing the whole.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 9-1288 filed by the present applicant has been known as a method and apparatus for molding a mold as described above. As the pre-compression, a tubular thin annular body slightly smaller than the inner surface of the casting frame is inserted into the molding sand with a predetermined compression force to perform pre-compression.

[0003]

However, in such pre-compression of molding sand, if the pattern side surface of the pattern plate on which the tall pattern is attached is close to the inner surface of the casting frame, the thin plate ring is formed. When the body is inserted into the gap, the molding sand is restricted from moving in the lateral direction, the molding sand is compressed to a high sand density at this part, and the pattern plate is made of weak material such as wood In this case, there is a problem that the molding plate compressed at a high density causes damage such as deformation or cracking of the pattern plate. In the case of a flat pattern plate with a low pattern height, the molding sand moves in the horizontal direction even when the thin annular body is inserted into the molding sand, and the thin annular body directly presses the upper surface of the pattern plate. As a result, there is a problem that the pattern plate is damaged. An object of the present invention is to provide a method and an apparatus for pre-compressing molding sand without damaging a pattern plate, which has been made in view of the above problems.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, a method for pre-compressing molding sand according to the present invention is directed to a method for molding sand injected into a space defined by a pattern plate and a molding flask. A method for pre-compressing molding sand in a mold for pressing the entire molding sand upper surface after pre-compressing molding sand near the inner surface of the molding flask, wherein a tubular thin plate annular body slightly smaller than the inner surface of the molding flask is formed. And inserting the thin plate annular body relative to the pattern plate from above the molding sand until the insertion depth dimension or the insertion load value of the thin plate annular body with respect to the molding sand preset according to the pattern plate is reached. The first pre-compression device for molding sand in the present invention is a device for pre-compressing molding sand in the vicinity of the inner surface of a molding flask with respect to the molding sand introduced into the space defined by the pattern plate and the molding flask. Pre-compressed A pre-compression device for molding sand in a mold mold that later presses the entire upper surface of the molding sand, and has a cylindrical shape slightly smaller than the inner surface of the casting frame above a lifting table that can be raised and lowered by a hydraulic cylinder. The thin plate annular body formed in the above is disposed so as to be able to move up and down relatively to the lifting table, and a displacement meter for measuring the displacement is connected to the lifting table or the thin plate annular body, and the displacement meter is set in advance. It is electrically connected to a hydraulic control valve of the hydraulic cylinder via a controller that transmits a signal for stopping the extension operation of the hydraulic cylinder according to the insertion depth dimension of the thin plate annular body with respect to the molding sand, The second pre-compression device for molding sand in the present invention is a device for pre-compressing molding sand near the inner surface of a casting flask with respect to molding sand charged into a space defined by a pattern plate and a molding flask. A pre-compression device for molding sand in a mold mold that presses the entire molding sand upper surface, above a lifting table that can be raised and lowered by a hydraulic cylinder, on a lower surface of a frame, via a load sensor to an inner surface of the molding frame. The thin plate annular body formed in a relatively small cylindrical shape is disposed so as to be able to move up and down relatively with respect to the elevating table, and the load sensor is set to a predetermined insertion load value for the molding sand of the thin plate annular body. A third molding sand pre-compressing apparatus according to the present invention, wherein the apparatus is electrically connected to a hydraulic control valve of the hydraulic cylinder via a controller that transmits a signal for stopping the extension operation of the hydraulic cylinder in response to the signal. Is a method of molding a molding sand in which the molding sand near the inner surface of the molding flask is pre-compressed against the molding sand charged into the space defined by the pattern plate and the molding flask, and then the entire molding sand upper surface is pressed. A pre-compression device for molding sand in a mold, having a cylindrical shape slightly smaller than the inner surface of the casting frame via a load sensor on a lower surface of a frame above a lifting table which can be raised and lowered by a hydraulic cylinder. The thin plate annular body formed in the above is disposed so as to be able to move up and down relatively with respect to the lifting table, and a displacement meter for measuring the displacement is connected to the lifting table, and the load sensor and the displacement meter are set in advance. The controller transmits a signal to stop the extension operation of the hydraulic cylinder by either one of the signal of reaching the insertion load value or the signal of reaching the insertion depth dimension to the molding sand of the thin plate annular body. It is characterized by being electrically connected to a hydraulic control valve of a hydraulic cylinder.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1, an upward hydraulic cylinder 2 is erected on a base 1, and an elevating table 3 is fixed to a tip of a piston rod of the hydraulic cylinder 2. A pattern plate 4 having a pattern provided thereon is attached to an upper portion of the elevating table 3, and a casting frame 5 and a filling frame 6 are mounted on the pattern plate 4 to form the pattern plate 4 and the casting frame 5 ( (Including the filling frame 6) and the molding sand S is introduced into the space defined by the molding sand S. Above the elevating table 3, a thin annular member 10 is fixed to the lower surface of the frame 7 via a mounting base 8 and a mounting plate 9. Note that the thin plate-shaped annular body 10 is
Is formed in a slightly smaller cylindrical shape relative to the inner surface of the casting frame 5 so as to be relatively insertable into the casting flask 5.

Further, a displacement meter 11 for measuring the upward displacement of the lifting table 3 is provided on the base 1 by connecting the tip of a rod 12 to the side of the lifting table 3.
The displacement gauge 11 controls the hydraulic cylinder 2 via a controller 13 that transmits a signal for stopping the extension operation of the hydraulic cylinder 2 in accordance with a preset insertion depth of the thin plate annular body 10 into the molding sand S. It is electrically connected to the hydraulic control valve 14. That is, from the displacement meter 11, the height position (the depth dimension at which the thin plate-shaped annular body 10 is inserted into the molding sand S) when the lifting table 3 is raised is transmitted to the controller 13 every moment. The vessel 13 receives a signal notifying that the insertion depth of the thin annular member 10 has reached the preset depth corresponding to the pattern plate 4 and outputs a signal to the hydraulic control valve 14 of the hydraulic cylinder 2 to control the hydraulic pressure. The valve 14 is operated to stop the hydraulic cylinder 2 from rising.

[0007] In the above-described structure, the insertion depth of the thin annular member 10 into the molding sand set in advance according to the shape of the pattern plate 4 to be used is controlled by the controller 13.
Has been entered. In this state, the casting frame 5 and the filling frame 6 are placed on the pattern plate 4 above the elevating table 3, and after the molding sand S is put into the space defined by the pattern plate 4, the casting frame 5 and the filling frame 6. The hydraulic cylinder 2 is actuated to raise the pattern plate 4 and the like above the elevating table 3 so that the thin plate-shaped annular body 10 is inserted into the molding sand S, and the molding sand S is pre-compressed and measured by the displacement meter 11. The lift displacement (height) of the lifting table 3 is output to the controller 13 and the measured value is set at a predetermined height position (the depth dimension at which the thin plate annular body 10 is to be inserted into the molding sand S). When it reaches, a signal is output to the hydraulic control valve 14, and the hydraulic valve 14 is operated to stop the raising of the hydraulic cylinder 2, so that the state shown in FIG. 1 is reached and the preliminary compression of the molding sand is completed. Next, the hydraulic cylinder 2 contracts to extract the thin plate annular body 10 from the molding sand S, and then presses the entire molding sand by the operation of the pressing means (not shown) and the hydraulic cylinder 2 to perform mold molding.

Next, the pre-compression device for molding sand in FIG. 2 will be described. 2 is different from the device of FIG. 1 in that a mounting base 8 is mounted on the lower surface of the frame 7 via a load sensor 11A, and the load sensor 11A is electrically connected to the controller 13. Have been.
In this case, the controller 13 sets the load sensor 11 to a preset insertion load value of the thin annular member 10 into the molding sand S.
When the measured value of A is reached, a signal for stopping the extension operation of the hydraulic cylinder 2 is sent to the hydraulic control valve 14 of the hydraulic cylinder 2.
To be output. In addition, the displacement meter 11 shown in FIG. In the casting sand pre-compression device of FIG. 2 configured as described above, the thin plate annular body 10 is inserted into the casting sand S to pre-compress the casting sand S in the same manner as in FIG. When the measurement signal from the sensor 11A reaches a preset load value of the thin annular member 10, the controller 13 sends the hydraulic valve 1 of the hydraulic cylinder 2
4 is transmitted to stop the extension operation of the hydraulic cylinder 2. Thereafter, the molding of the mold is performed in the same manner as the operation of FIG.

Next, the pre-compression device for molding sand in FIG. 3 will be described. In the apparatus shown in FIG. 3, the displacement meter 1 shown in FIG.
1 and the load sensor 11A in FIG. 2 are respectively provided at the same position, and are electrically connected to the respective common controllers 13. In this case, the controller 13 sends the hydraulic cylinder 2 based on one of a signal indicating that the insertion depth of the thin annular member 10 to the molding sand S has been reached and a signal indicating that the insertion load value has been reached. Is transmitted to the hydraulic valve 14 to stop the extension operation of the hydraulic cylinder. Therefore, the pre-compression of the molding sand is controlled by both the insertion depth dimension and the insertion load value of the thin annular plate 10 into the molding sand which are set in advance, and the extension operation of the hydraulic cylinder 2 is stopped. The lifting table 3 shown in FIGS. 1, 2 and 3 and the thin plate-shaped annular body 10 are relative to each other, and the lifting table 3 is fixed, and the thin plate-shaped annular body 10 is moved up and down by a hydraulic cylinder. Is also good. In this case, the displacement gauge 11 shown in FIGS. 1 and 3 is mounted on a frame 7 on which a hydraulic cylinder is mounted, and its rod is connected to a mounting base 8 or a mounting plate 9.

[0010]

As is apparent from the above description, the present invention pre-compresses the molding sand by the thin annular member according to the predetermined insertion depth or insertion load of the thin annular member into the molding sand. As a result, even if the pattern plate is made of a material having low strength such as wood, the pattern plate can be formed without damaging the material, and the effect is remarkable.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing still another embodiment of the present invention.

[Explanation of symbols]

 2 Hydraulic cylinder 3 Lifting table 4 Pattern plate 5 Casting frame 10 Thin annular body 11 Displacement gauge 11A Load sensor 13 Controller 14 Hydraulic control valve S Casting sand

Claims (4)

[Claims] 1. A molding method in which molding sand near an inner surface of a molding flask is pre-compressed against molding sand introduced into a space defined by a pattern plate and a molding flask, and then the entire molding sand upper surface is pressed. A method for pre-compressing molding sand, in which a tubular annular plate slightly smaller than the inner surface of the casting flask is inserted into the molding sand in a predetermined depth according to the pattern plate. A pre-compression method for molding sand, wherein the molding sand is relatively inserted from above the molding sand toward the pattern plate until the insertion load value is reached. 2. A molding method in which molding sand near an inner surface of a molding flask is pre-compressed against molding sand introduced into a space defined by a pattern plate and a molding flask, and then the entire molding sand upper surface is pressed. A pre-compression device for molding sand, which is above a lifting table 3 which can be raised and lowered by a hydraulic cylinder 2;
An annular thin plate 10 formed in a cylindrical shape slightly smaller than the inner surface of the casting frame 5 is disposed so as to be able to move up and down relatively with respect to the elevating table 3. And a signal for stopping the extension operation of the hydraulic cylinder 2 in accordance with a predetermined insertion depth of the thin annular member 10 into the molding sand S. A pre-compression device for molding sand, electrically connected to a hydraulic control valve 14 of the hydraulic cylinder 2 via a controller 13 for transmitting. 3. A molding method in which molding sand near an inner surface of a molding flask is pre-compressed against molding sand introduced into a space defined by a pattern plate and a molding flask, and then the entire molding sand upper surface is pressed. A pre-compression device for molding sand, which is above a lifting table 3 which can be raised and lowered by a hydraulic cylinder 2;
On the lower surface of the frame 7, a thin annular plate 10 formed in a cylindrical shape slightly smaller than the inner surface of the casting flask 5 via a load sensor 11 </ b> A is provided so as to be able to move up and down relatively to the elevating table 3. The load sensor 11A is connected to the hydraulic cylinder 2 via a controller 13 that transmits a signal for stopping the extension operation of the hydraulic cylinder 2 in accordance with a preset insertion load value of the thin annular member 10 into the molding sand S. A preliminary compression device for molding sand, electrically connected to the hydraulic control valve (14). 4. A molding method in which molding sand near an inner surface of a molding flask is pre-compressed against molding sand introduced into a space defined by a pattern plate and a molding flask, and then the entire molding sand upper surface is pressed. A pre-compression device for molding sand, which is above a lifting table 3 which can be raised and lowered by a hydraulic cylinder 2;
On the lower surface of the frame 7, a thin annular plate 10 formed in a cylindrical shape slightly smaller than the inner surface of the casting flask 5 via a load sensor 11 </ b> A is provided so as to be able to move up and down relatively to the elevating table 3. And a displacement meter 11 for measuring the displacement thereof is connected to the lifting table 3.
The extension operation of the hydraulic cylinder 2 is performed by the signal 1A or the signal which has reached the insertion depth value of the preset insertion load value for the casting sand S of the thin plate annular body 10 or the signal which has reached the insertion depth. An apparatus for pre-compressing molding sand, wherein the apparatus is electrically connected to a hydraulic control valve 14 of the hydraulic cylinder 2 via a controller 13 for transmitting a stop signal.