JP7806554B2 - Sand cutter for cutting molds - Google Patents

Description

This invention relates to a mobile sand cutter for cutting molds that can sand-cut the anti-cavity surface of a mold that has been molded higher than the height of the molding die to any desired height.

In order to produce casting materials without being restricted by the height of the flask, there is a demand for equipment that can mold the upper mold higher than the height of the flask and place a weight on top of it. This has created a need to sand-cut the anti-cavity surface of a top-up mold that is higher than the height of the flask to the desired height.

Patent Document 1 describes a fixed-type sand cutter in which the cutter blade mount is supported on a horizontal rotating shaft installed below the mold transfer line, and a cylinder is used to rotate the cutter blade mount and raise the cutter blade, thereby cutting away excess sand from the mold as it moves along the transfer line. However, because the cutter blade mount's rotating shaft is fixed in this structure, it is not possible to sand cut the anti-cavity surface of the build-up mold at any desired height.

Patent Document 2 describes a mobile sand cutter that cuts excess sand by reciprocating a blade below the mold conveyance line in a direction perpendicular to the conveyance line. However, because the path of the reciprocating movement is fixed and the height of the sand-cutting surface cannot be changed, it is not possible to sand-cut the anti-cavity surface of the forming mold at any desired height.

Furthermore, when sand-cutting the opposite cavity surface of a mold that has been molded higher than the height of the crucible using the fixed sand cutter of Patent Document 1, the mold on the leading edge of the cutter blade can be damaged by the reaction force generated during sand-cutting, thereby negating the advantage of molding a mold higher than the height of the crucible.

Japanese Patent Application Laid-Open No. 2005-199305 JP 2014-057988 A

The first object of the present invention is to provide a sand cutter for cutting molds that can sand cut the anti-cavity surface of a mold that is higher than the height of the molding frame to any desired height. The second object of the present invention is to provide a sand cutter for cutting molds that can prevent damage to the mold on the leading edge of the cutter blade due to the reaction force during sand cutting.

The invention of claim 1, made to solve the above object , comprises a sand-cutting mechanism having a tool post on which a cutter blade is attached, a tool post lifting actuator that raises and lowers the tool post and can stop it midway through the lifting and maintain the height of the tool post, a position detection sensor that can detect the height of the tool post, a traverse actuator that allows the sand-cutting mechanism to move traversely, and a backup unit having a pressure plate that can be pressed against the build-up mold on the cutting edge side of the cutter blade, and is characterized in that the sand-cutting mechanism controls the height of the pressure plate of the backup unit in conjunction with the height of the tool post .

The invention of claim 2 is the invention of claim 1, further comprising a backup unit having a presser plate that can be pressed against the deposit mold on the cutter blade leading end side and can be stopped midway through its movement and held at the stop position, an elevation actuator that raises and lowers the presser plate and can stop it midway through its movement and hold it at the stop position, and a second position detection sensor that can detect the height of the presser plate. The presser plate of the backup unit can be pressed against the deposit mold to prevent damage to the deposit mold on the cutter blade leading end side.

The sand cutter for cutting molds of claim 1 can be configured to control the height of the tool post using the position detection sensor to a height that will sand cut a predetermined amount of sand based on mold height information after molding. Alternatively, the height of the tool post can be controlled using the position detection sensor to a mold height that is input in advance as molding conditions required for molding a mold set for each model. Furthermore, a backup unit is provided that includes a pressure plate that can be pressed against the build-up mold on the cutter blade leading end side and can be stopped midway through its movement and held at the stop position, an elevation actuator that can raise and lower the pressure plate and can be stopped midway through its elevation and held at the stop position, and a second position detection sensor that can detect the height of the pressure plate. The height of the pressure plate of the backup unit can be controlled using the second position detection sensor in conjunction with the controlled height of the tool post.

The sand cutter for cutting molds of the present invention can sand cut the anti-cavity surface of a mold that is higher than the height of the molding frame to any desired height. Furthermore, the sand cutter of the present invention, which is equipped with a backup unit, can prevent damage to the mold on the leading end side of the cutter blade due to the reaction force during sand cutting.

This is a front view showing a flask-attached mold with a weight placed on an upper mold whose anti-cavity surface is sand-cut at the edge level of the upper frame. This is a front view showing a flask-attached mold with a weight placed on an upper mold whose anti-cavity surface has been sand-cut at a position higher than the end level of the upper frame. FIG. 2 is a front view showing the entire mold making line. FIG. 1 is a front view showing the sand cutter of the embodiment, showing the original position when sand-cutting the anti-cavity surface of the build-up mold at a position higher than the end of the metal frame. 4 is a plan view of the sand cutter (viewed along the arrows A-A in FIG. 4 ). 4 is a side view of the sand cutter (view along arrows B-B in FIG. 4). 4 is a side view of the backup unit (viewed along the CC arrows in FIG. 4). This is a front view showing the original position when sand-cutting the anti-cavity surface of the lower mold at the end level of the metal frame. 8 is a partial side view of the sand cutter (view taken along the arrows D-D in FIG. 8). FIG. 2 is a plan view of the position detection sensor. FIG. 10 is a front view showing the state before sand cutting of the deposit mold at the highest position above the end of the metal frame on the anti-cavity side (the retainer plate of the backup unit advances). This is a front view showing the state before sand cutting of the build-up mold at a position slightly higher than the edge of the metal frame on the opposite cavity side (the retaining plate of the backup unit advances). FIG. 10 is a front view showing the state in which the build-up mold has been sand-cut at a position higher than the end of the metal frame on the opposite cavity side. FIG. 10 is a front view showing the state in which the pressing plate of the backup unit is being cleaned after sand-cutting the build-up mold at a position higher than the end of the metal frame on the anti-cavity side. This is a front view showing the state in which the lower mold has been sand-cut at the edge level of the metal frame on the opposite side of the cavity (without operating the backup unit).

An embodiment of the present invention will be described below.
FIG. 1 is a front view of a flask-mounted mold with a lower mold 2a and an upper mold 2b mounted on a surface platen cart 4. The upper mold 2b has its anti-cavity surface 5 sand-cut at the edge level of the upper frame 3b, and a weight 1 is placed on top of it. FIG. 2 is a front view of a flask-mounted mold with a lower mold 2a and a top mold 2c mounted on a surface platen cart 4. The top mold 2c has its anti-cavity surface 5 sand-cut at a position higher than the edge level of the upper frame 3b, and a weight 1 is placed on top of it. In order to mount the lower mold 2a, upper mold 2b, or top mold 2c, and weight 1 on the surface platen cart 4, it is necessary to sand-cut the anti-cavity surface 5 of the lower mold 2a, which contacts the surface platen cart 4, and the anti-cavity surface 5 of the upper mold 2b or top mold 2c, which contacts the weight 1, flat. 3a denotes the lower frame.

(Overall structure)
3 is a front view showing the entire mold making line 6. A frame feed pusher 7 is arranged on the entrance side of the mold making line 6, and a cushion device 8 is arranged on the exit side. The upper mold 2b or the build-up mold 2c and the lower mold 2a are sandwiched between the frame feed pusher 7 and the cushion device 8 and transported frame by frame on a roller conveyor 9 of the mold making line 6 in the direction of the arrow. The upper molds 2b, 2c and the lower mold 2a are transported alternately on the roller conveyor 9.

The mold making line 6 is equipped, from its entry side to its exit side, with an empty frame carry-in traverser 10, an empty frame separation device 11, a molding machine 12, an upper and lower frame inverting machine 13, the sand cutter 31 of the present invention, a surface plate setting device 15, an upper frame inverting machine 16, a frame alignment device 17, and an aligned frame carry-out traverser 18. Note that devices not related to the transport of the upper and lower molds, such as a sprue boring device, gas hole drilling device, and core setting device, are omitted from this diagram.

The upper and lower frames 3b and 3a, which are carried into the mold-making line 6 by the empty frame carrying traverser 10, are separated by the empty frame separating device 11 and sent alternately to the molding machine 12, with the upper frame 3b leading the way. In the molding machine 12, an upper mold 2b or a top-up mold 2c is made inside the upper frame 3b, and a lower mold 2a is made inside the lower frame 3a. The molding machine 12 is equipped with a function to detect the mold height after molding. The molded upper mold 2b or top-up mold 2c and lower mold 2a are then turned upside down by the frame inverter 13 and placed on the roller conveyor 9 with the anti-cavity surface 5 facing downwards.

Then, the lower mold 2a is sand-cut by the sand cutter 31 of the present invention at a position where the anti-cavity surface 5 is aligned with the edge level of the lower frame 3a, and the upper mold 2b or the raised mold 2c is sand-cut at a position where the anti-cavity surface 5 is aligned with the respective set height. The structure and operation of the sand cutter 31 of the present invention will be described later.

The surface plate cart 4 is transported to the surface plate setting device 15 via a separate route (not shown). In the surface plate setting device 15, the surface plate cart 4 is set on the lower mold 2a, and only the upper mold 2b or the top-up mold 2c is re-inverted by the upper frame inverting machine 16 so that the anti-cavity surface 5 faces up. Next, the upper mold 2b or the top-up mold 2c is lifted by the frame alignment device 17, and placed on top of the lower mold 2a that has been brought below the frame alignment device 17, completing the frame alignment. After the frame alignment, the upper and lower molds are transported to the subsequent process by the frame ejection traverser 18. Then, in a subsequent process (not shown), a weight 1 is placed on the top surface of the sand-cut upper mold 2b or the top-up mold 2c, and molten metal is poured.

(Sand Cutter)
The structure of the sand cutter 31 will be described below with reference to Figures 4 to 6. The sand cutter 31 is installed below the roller conveyor 9 of the mold making line 6. As shown in Figure 5, two guide pins 35 are arranged in a direction perpendicular to the mold transport direction, and the sand cutting mechanism 14 placed on a guide pin holder 33 can be moved laterally by a traverse actuator 34. Here, traverse means movement in a direction perpendicular to the mold transport direction.

The sand-cutting mechanism 14 has two guide pins 21 fixed vertically to its left and right frames. The left and right guide pin holders 22 are connected by a tool post 20, which can be raised and lowered by a tool post lift actuator 19. The tool post lift actuator 19 uses a hydraulic cylinder that is raised and lowered by a center-closed three-position solenoid valve, or an electric cylinder with a brake, and has the ability to stop mid-lift and hold the mechanism in a stopped position. In this embodiment, to make the sand-cutting mechanism 14 more compact, a hydraulic cylinder that is raised and lowered by a center-closed three-position solenoid valve is used.

A position detection sensor 23 is fixed near one side of the guide pin 21, parallel to the guide pin 21, and can continuously detect the height of the tool post 20. As shown in Figure 6, a pointer 25 is attached to the guide pin holder 22, which moves up and down along the guide pin 21, to detect the height of the tool post 20. Details of this part are shown in Figure 10. In this embodiment, the position detection sensor 23 is a linear encoder, but instead, a distance sensor may be used to detect the height of the tool post 20.

As shown in Figures 4 and 5, cutter blades 26 are attached to the tool rest 20 and extend the entire length of the mold. In this embodiment, the cutter blades 26 are arranged in two rows, one at the front and one at the back, but they may also be arranged in a single row. Figure 4 shows how the build-up mold 2c formed within the upper frame 3b is sand-cut by the cutter blades 26.

The upper mold 2b or the build-up mold 2c and the lower mold 2a are transported on a roller conveyor 9 consisting of rollers 36 and side rollers 37. With the transported molds stopped, the sand-cutting mechanism 14 is moved laterally by the traversing actuator 34 as shown in Figure 4, and the part indicated by S in Figure 4 is sand-cut.

Note that Figures 4 to 6 show sand cutting at a position higher than the upper frame 3b of the forming mold 2c, while Figures 8 and 9 show sand cutting at the edge level of the lower frame 3a of the anti-cavity surface 5 of the lower mold 2a.

(Sand cut level)
The control of the sand cutting level is described below. Here, the sand cutting amount refers to the height of the sand mold that is cut from the mold height after molding, and the sand cutting level refers to the height of the sand mold obtained after sand cutting. The sand cutting level is controlled by matching the height of the tool post 20 detected by the position detection sensor 23 to a level instructed by a control means (not shown). The sand cutting level can be controlled in two ways. The first method is based on the mold height information after molding sent from the molding machine 12. That is, the height of the tool post 20 detected by the position detection sensor 23 is controlled based on the mold height information after molding and the sand cutting amount input in advance. For example, if the sand cutting amount is input as 1 mm, the mold height after molding is controlled to be sand cut by 1 mm. By sand cutting based on the mold height after molding in this way, damage to the mold formed by sand cutting, which is caused by the reaction force when molding a mold formed above the height of the upper frame 3b, can be reduced.

The second method is to control the height of the tool post 20 to the mold height that is input in advance into the molding conditions required for molding the mold set for each model. For example, if the mold height after sand cutting is input as the height of the upper frame 3b + 50 mm, the control will always ensure that sand cutting is at the height of the upper frame 3b + 50 mm, even if the mold height after molding changes. By keeping the mold height after sand cutting constant for each model, the pouring conditions (height from the ladle to the cavity) can be kept constant.

In the above embodiment, only the upper mold was raised above the height of the metal frame, but the lower mold may also be raised above the height of the metal frame and then sand-cut.

(backup unit)
Next, the backup unit 32 for preventing damage to the build-up mold on the cutting edge side of the cutter blade will be described.
As shown in FIG. 7 , two guide pins 46 are vertically mounted on a fixed frame 45 on the cutter blade leading edge side. The lifting platform 41, with guide pin holders 47 on both sides held by these guide pins 46, is raised and lowered by a lifting actuator 40. The lifting actuator 40 uses a hydraulic cylinder or an electric cylinder with a brake, which is raised and lowered by a center-closed three-position solenoid valve that can stop mid-lift and maintain the stop position. The lifting platform 41 is raised and lowered in accordance with the sand-cut level of the mold. As described below, a pressure plate 39 is mounted on the lifting platform 41, and the height of the pressure plate 39 is continuously detected by a second position detection sensor 42. The second position detection sensor 42 is fixed parallel to the guide pins 46 and has a pointer 48 attached to the guide pin holder 47 that rises and falls to detect the height of the pressure plate 39. In this embodiment, a linear encoder is used as the second position detection sensor 42. Alternatively, a distance sensor may be used to detect the height of the tool post 20.

As shown in Figure 7, the lifting platform 41 is provided with two horizontal guide pins 44, and the pressure plate 39 holds the guide pin holders 43 on both sides of it on these guide pins 44, and as shown in Figure 11, is moved by the horizontal actuator 38 toward the forming mold 2c on the cutter blade leading end side. Similar to the lifting actuator 40, the horizontal actuator 38 is preferably a hydraulic cylinder or an electric cylinder with a brake that is raised and lowered by a center-closed three-position solenoid valve that can hold an intermediate stop position. The pressure plate 39 advances until it comes into close contact with the side of the forming mold 2c, and then stops.

To ensure that the pressure plate 39 is tightly attached to the forming mold 2c without creating a gap, the horizontal actuator 38 must have a sufficient stroke and must not damage the forming mold 2c with the pressing force of the pressure plate 39. Therefore, in this embodiment, a pressure reducing valve is provided in the hydraulic circuit of the horizontal actuator 38 to control the pressing force of the pressure plate 39. Furthermore, a pressure switch (not shown) detects a rise in pressure in the hydraulic circuit, and when it detects that the pressure plate 39 has tightly attached to the forming mold 2c, the center-closed three-position solenoid valve is returned to its neutral position, thereby maintaining the extrusion position of the pressure plate 39. By maintaining the extrusion position of the pressure plate 39 with the center-closed three-position solenoid valve in this way, the reduced-pressure extrusion force is not defeated by the thrust of the traverse actuator 34, which moves the sand-cutting mechanism 14 laterally, and the formation mold 2c can be backed up.

The sand cutting mechanism 14 controls the height of the pressure plate 39 using the second position detection sensor 42 in conjunction with the sand cutting height commanded by the control means. For example, it controls the height of the pressure plate 39 so that its lower surface is positioned 5 mm higher than the tip of the cutter blade 26. By controlling the height of the pressure plate 39 in conjunction with the height of the cutter blade 26 in this way, it is possible to prevent collision between the cutter blade 26 and the pressure plate 39, which backs up the build-up mold 2c at a position close to the cutter blade 26.

Because the pressure plate 39 has a thickness in the height direction, it can only back up the forming mold 2c up to a height where it does not interfere with the frame. If sand-cutting a low forming mold 2c where the pressure plate 39 would interfere with the frame, the backup unit 32 is not activated, and control is exercised to sand-cut the forming mold 2c without backing it up.

(effect)
Next, the operation of the sand cutter for cutting molds of the present invention will be described.
Figure 11 shows the state in which the cutter blade 26 of the sand-cutting mechanism 14 and the pressure plate 39 of the backup unit 32 are at their lowest positions, with the pressure plate 39 in close contact with the mold 2c, in order to sand-cut the mold 2c at the highest position above the upper frame 3b on the anti-cavity side. From this state, the cutter blade 26 is moved laterally as shown in Figure 13, and the portion indicated by S in Figure 11 is sand-cut. The mold 2c on the cutter blade leading end side is supported and backed up by the pressure plate 39, so it is not destroyed during sand-cutting. Thereafter, as shown in Figure 14, it is preferable to retract and then raise the pressure plate 39 of the backup unit 32, and clean the mold-pressing surface of the pressure plate 39 with a fixed brush 49.

Figure 12 shows the cutter blade 26 of the sand-cutting mechanism 14 and the pressure plate 39 of the backup unit 32 at an intermediate height in order to sand-cut the build-up mold 2c at a position slightly higher than the upper frame 3b on the anti-cavity side. As shown by the phantom line in Figure 12, the pressure plate 39 is advanced to come into close contact with the build-up mold 2c, and the cutter blade 26 is moved laterally to sand-cut the portion indicated as S in Figure 12.

As mentioned above, the pressure plate 39 has a thickness in the height direction. Therefore, if it is raised to a position higher than that shown in Figure 12, it will interfere with the metal frame, and the pressure plate 39 will not be able to adhere tightly to the forming mold 2c and back it up. For this reason, when sand-cutting the forming mold 2c at a position higher than that shown in Figure 12, the backup unit 32 is not activated, and the forming mold 2c is sand-cut without being backed up.

Figure 15 shows the state in which the lower mold 2a is sand-cut at the edge level of the lower frame 3a on the anti-cavity side. In this case, there is no part to which the presser plate 39 can be attached to the lower mold 2a, so sand-cutting is performed without operating the backup unit 32. In this case, there is no risk of the lower mold 2a being damaged by the cutting edge of the cutter blade.

(summary)
As described above, the present invention has the following advantages.
(1) In a molding line where a weight is placed on the upper frame to prevent it from floating up when pouring molten metal, by combining it with a molding machine that can mold molds higher than the height of the frame, it is possible to produce castings that are larger than the height of the frame.
(2) By backing up the mold build-up on the cutting edge side of the cutter blade, damage to the mold build-up due to the reaction force when sand-cutting a mold built up to a height greater than the frame height can be prevented.
(3) By combining with a molding machine having a function for detecting the height of the mold after molding and performing sand cutting based on the height of the mold after molding, it is possible to reliably prevent damage to the mold that has been molded to a height higher than the frame height due to the reaction force when sand cutting.
(4) By sand cutting based on the mold height that has been input in advance into the molding conditions, the pouring conditions (height from the ladle to the cavity) can be made constant.
(5) By raising and lowering the pressure plate in conjunction with the height of the tool rest, it is possible to prevent collision between the pressure plate, which backs up the mold at a position close to the cutter blade, and the cutter blade.

1 Weight 2a Lower mold 2b Upper mold 3a Lower frame 3b Upper frame 4 Surface plate cart 5 Opposite cavity surface 6 Mold molding line 7 Frame feed pusher 8 Cushion device 9 Roller conveyor 10 Empty frame carry-in traverser 11 Empty frame separation device 12 Molding machine 13 Upper and lower frame inverting machine 14 Sand cutting mechanism 15 Surface plate setting device 16 Upper frame inverting machine 17 Frame alignment device 18 Alignment frame carry-out traverser 19 Tool post lifting actuator 20 Tool post 21 Guide pin 22 Guide pin holder 23 Position detection sensor 24 Frame 25 Pointer 26 Cutter blade 31 Sand cutter 32 Backup unit 33 Guide pin holder 34 Lateral movement actuator 35 Guide pin 36 Roller 37 Side roller 38 Horizontal actuator 39 Presser plate 40 Lifting actuator 41 Lifting platform 42 Second position detection sensor 43 Guide pin holder 44 Guide pin 45 Fixed frame 46 Guide pin 47 Guide pin holder 48 Pointer 49 Fixed brush S Portion of mold to be sand cut

Claims (6)

A sand cutter for cutting molds, comprising: a tool post on which a cutter blade is attached; a tool post lifting actuator that raises and lowers the tool post and can stop it midway through the lifting and maintain the height of the tool post; a sand cutting mechanism having a position detection sensor that can detect the height of the tool post ; a traverse actuator that allows the sand cutting mechanism to move traversely; and a backup unit having a pressure plate that can be pressed against the forming mold on the cutting blade leading end side, wherein the sand cutting mechanism controls the height of the pressure plate of the backup unit in conjunction with the height of the tool post . The sand cutter for cutting molds described in claim 1 is equipped with a backup unit having a pressure plate that can be pressed against the forming mold on the cutting edge side of the cutter blade and can stop midway through its movement and be held at the stop position, an elevation actuator that can raise and lower the pressure plate and stop midway through its movement and be held at the stop position, and a second position detection sensor that can detect the height of the pressure plate. A sand cutter for cutting molds as described in claim 2, wherein the backup unit's pressure plate can be pressed against the build-up mold to prevent damage to the build-up mold on the cutter blade leading end side. The sand cutter for cutting molds described in claim 1, wherein the height of the tool post is controlled using the position detection sensor to a height that performs sand cutting of a predetermined amount of sand based on mold height information after molding. A sand cutter for cutting molds as described in claim 1, in which the height of the tool post is controlled using the position detection sensor to a mold height that is input in advance as a molding condition required for molding a mold set for each model. a backup unit including a presser plate that can be pressed against the forming mold on the cutter blade leading end side and can be stopped midway through its movement and held at the stop position, an elevation actuator that raises and lowers the presser plate and can be stopped midway through its elevation and held at the stop position, and a second position detection sensor that can detect the height of the presser plate;
2. The sand cutter for cutting molds according to claim 1 , wherein the height of the presser plate of the backup unit is controlled by using the second position detection sensor in conjunction with the controlled height of the tool rest.