Mold pressing device

Abstract

To provide a mold pressing device that is detachable from a T-groove and suitable for moving a mold to a reference position on a table provided inside a molding machine. [Solution] When pressurized oil is supplied from the hydraulic port 31 to the fixing cylinder chamber 35, the fixing piston 42 pulls up the T-leg 40 and engages it with the T-groove of the bolster. The sequence valve housing 60 is configured with a sequence valve that opens when the hydraulic pressure on the inlet side exceeds a predetermined value, and opens when the pressure of the pressurized oil in the fixing cylinder chamber 35 exceeds the predetermined pressure. When pressurized oil is supplied from the sequence valve to the push cylinder chamber 56, the push piston 52 moves the pressing portion 51 in the longitudinal direction D of the T-groove.

Description

Technical Field

[0001] The present invention relates to a mold pushing device that moves a mold to a reference position on a table provided in a press device, an injection molding machine, a forging device, or the like.

Background Art

[0002] In a press device, an injection molding machine, a forging device, etc. (hereinafter generally referred to as a molding device) that forms a workpiece using a mold, the mold is replaced every time the form of the workpiece to be formed changes. Also, since the mold is generally heavy, the replacement work requires a lot of time, which causes a decrease in the operating rate of the molding device. In a large molding device such as a transfer press, as known in, for example, Patent Document 1, a moving bolster that moves the mold from the inside to the outside of the molding device body with the mold placed on a bolster (lower table) is used.

[0003] On the other hand, many molding devices with the table fixed inside the main body are also used. For such a molding device, for example, in Patent Document 2, a plurality of horizontally foldable rails are provided substantially in parallel on the front (or rear) of a bolster provided in a press device, the mold is placed on these rails, and the mold is moved along the rails to the bolster side to carry the mold onto the bolster. A die lifter is provided on the bolster to lift and roll the mold on the bolster. The mold arranged in front of the press device is pushed into the reference position of the press device using the die lifter.

[0004] Also, in the patent document, a workpiece exchange table is provided on the side of a processing machine, the workpiece exchange table and the processing machine are connected by an intermediate rail, and a workpiece placed on the workpiece exchange table is pressed toward the processing machine side by push-pull driving means provided on the workpiece exchange table to carry the workpiece into the processing machine.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-137509 [Patent Document 2] Japanese Utility Model Publication No. 50-87576 [Patent Document 3] Special Publication No. 7-119029 [Patent Document 4] Japanese Patent Application Publication No. 5-162042 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0006] In molding apparatuses where a table is fixed inside the main body, according to the technology described in Patent Documents 2 and 3, the mold can be easily transported to the front of the molding apparatus. However, since the die lifter is not equipped with a drive force to move the mold, the mold placed on the die lifter must ultimately be manually pushed into a reference position on the table provided inside the molding apparatus.

[0007] The table has positioning pins protruding from its rear side that indicate the reference position of the mold. When the mold is pushed in, a reference groove formed on the mold engages with the positioning pins, completing the positioning. The positioning pins are located deep inside the molding machine and become invisible from the front once the mold is mounted on the table. Furthermore, although the mold is heavy and easy to move on the die lifter, manually pushing the mold all the way to the back of the molding machine until the reference groove engages with the reference pins is hard work, and it is difficult to confirm whether it has been moved correctly.

[0008] In some facilities using molding equipment with a fixed table, after the mold is mounted on the table, a push cylinder is attached using the T-groove provided on the table, and the final pressing operation is performed by the pressing part of the push cylinder. As an example of such a push cylinder that utilizes a T-groove, the side push cylinder unit shown in Patent Document 4 (reference numeral 46 in the same document) is known. In such a side push cylinder unit, a separate pressure oil port is required for fixing to the T-groove, in addition to the pressure oil port for the operation of the pressing part. This is because the fixing operation to the T-groove and the operation of the pressing part are separate operations. In this case, connection work to each pressure oil port is required. Furthermore, in order to use such a side push cylinder unit in a mold pressing operation site, sequential control of the pressure oil is required, such as fixing to the T-groove and then operating the pressing part, which presents a problem as it requires a certain level of skill and time to handle.

[0009] The object of the present invention is to provide a mold pressing device that can be attached to and detached from a T-groove and is suitable for moving a mold to a reference position on a table provided in a molding apparatus.

[0010] The mold pressing device of the present invention is detachable from a T-groove on a table fixed within a molding apparatus, and presses a mold on the table in the longitudinal direction of the T-groove with a pressing part, A hydraulic port that receives pressurized oil from the outside, When pressurized oil is supplied from the hydraulic port to the fixing cylinder chamber, the fixing piston pulls up the T-leg and engages it with the T-groove, A sequence valve comprising a first side chamber and a second side chamber, wherein the pressure of the pressurized oil in the fixed cylinder chamber is transmitted to the first side chamber, and pressurized oil is supplied to the first side chamber from the hydraulic port, and the valve opens when the pressure in the first side chamber exceeds a predetermined pressure, The device includes a push piston that moves the pressing portion in the longitudinal direction of the T-groove when pressurized oil is supplied from the second side chamber to the push cylinder chamber. [Effects of the Invention]

[0011] According to the mold pressing device of the present invention, the process automatically switches from fixing the mold to the T-groove of the table to extending the pressing part to press the mold without any time loss, thus eliminating the need for skilled operators and allowing mold changes to be performed in a short time. Furthermore, only one connection to the hydraulic port is required. Moreover, since the pressing part begins to move only after it has been firmly fixed to the T-groove of the table, the push cylinder will not retract due to the weight of the mold. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1A shows a side view of the molding apparatus, and Figure 1B shows a plan view of the bolster, with the bolster fixed inside the main body of the molding apparatus. [Figure 2] This shows the six sides of the mold pressing device. [Figure 3] Figure 3A shows the cross-section of the mold pushing device during pressurized oil discharge, and Figure 3B shows the cross-section of XX. [Figure 4] Figure 4A shows the cross-section of the mold pushing device when pressurized oil is supplied, and Figure 4B shows the cross-section of XX. [Figure 5] This shows the process of fixing the mold to the bolster using a mold pressing device. [Best Mode for Carrying Out the Invention]

[0013] Embodiments of the present invention will be described below with reference to Figures 1 to 5. In this invention, in a mold pressing device utilizing a T-groove, pressurized oil can be supplied to both the fixing cylinder chamber and the pushing cylinder chamber by connecting to a single hydraulic port. Furthermore, since the mold pressing device will retract if it begins to extend before the mold is fixed to the T-groove, sequential control of the extension of the pressing part after fixing to the T-groove is also performed within the mold pressing device. In this invention, a sequence valve is used for sequential control, and the fixing cylinder chamber and the sequence valve are connected to a single hydraulic port. By monitoring the pressure in the fixing cylinder chamber with the sequence valve, fixing to the T-groove is detected and pressurized oil is supplied to the pushing cylinder chamber. This allows for automatic switching between fixing to the T-groove and movement of the pressing part without any time loss. A sequence valve is known as a pressure control valve that allows flow from the inlet side to the outlet side when the inlet pressure reaches a predetermined value.

[0014] Figure 1 shows a molding apparatus 1 to which the bolster 10 is fixed. Figure 1A is a side view of the molding apparatus 1, showing the bolster 10 cut at the die lifter 12. Figure 1B is a plan view of the bolster 10. The mold M is indicated by a dashed line. Mold M refers collectively to the upper mold M and the lower mold M1.

[0015] The molding apparatus 1 has an upper table (slide 20) and a lower table (bolster 10) fixed within the main body. The slide 20 is fitted with a hydraulic clamp (MT) 21 that specifically engages with the U-shaped cut provided in the upper mold. On the other hand, the bolster 10 is fitted with a general-purpose hydraulic clamp (LT) 22. Both hydraulic clamps 21 and 22 press and fix the upper mold M2 or the lower mold M1 to the slide 20 or the bolster 10.

[0016] The bolster 10 is embedded with a die lifter 12 that moves the mold M in the direction D from the front side to the back side of the molding apparatus 1. The die lifter 12 moves up and down by the pressure oil supplied from the outside through the hydraulic hose 11. A number of balls 13 are intermittently arranged in the direction D on the upper surface of the die lifter 12, enabling the movement of the mold not only in the direction D but also in the direction intersecting with the direction D (within the plane of FIG. 1B). When pressure oil is supplied to the die lifter 12, it rises and lifts the mold M from above the bolster 10. On the other hand, when the pressure oil is discharged, it descends, and the mold M is directly mounted on the bolster 10.

[0017] On the back side of the molding apparatus 1, a plurality of positioning pins 17, 18 project from the surface of the bolster 10. In the center of the bolster 10, a hole 19 is opened to discard unnecessary members cut out during the pressing process by the upper and lower molds M2, M1. Also, nine T-grooves 16 are provided on the front side and nine T-grooves 16 are provided on the back side of the bolster 10. The length direction of the T-grooves 16 is in the direction D.

[0018] On the front side of the molding apparatus 1, a detachable pre-roller 14 is attached. A number of rollers 15 are intermittently arranged along the direction D on the pre-roller 14. The mold M is suspended by a crane (not shown) and conveyed onto the pre-roller 14. The conveying surface of the rollers 15 coincides with the conveying surface of the balls 13 when the die lifter 12 rises, and the mold M is moved from the pre-roller 14 to the die lifter 12 without a step. The upper mold M2 is attached to the slide 20 by a hydraulic clamp (MT) 21, and the lower mold M1 is attached to the bolster 10 by a hydraulic clamp (LT) 22.

[0019] Figure 2 shows six views of the mold pressing device 100 of this embodiment. The mold pressing device 100 has vertically moving T-legs 40 protruding from the bottom surface of the cylinder housing 30. When the T-legs 40 are pulled up toward the cylinder housing 30, they engage with the T-groove 16 by sandwiching the upper wall of the T-groove 16 between the bottom surface of the cylinder housing 30 and the foot of the T-legs 40. A push housing 50 is provided on the right side of the cylinder housing 30. When the T-legs 40 are fitted into the T-groove 16, the push housing 50 moves the pressing portion 51 along the length direction (direction D) of the T-groove. A hydraulic port 31 that receives pressurized oil from the outside via a hydraulic hose 11 is provided on the left side of the cylinder housing 30. A sequence valve housing 60 is attached to the front of the cylinder housing 30.

[0020] Figure 3 shows a cross-section of the mold pushing device 100 when pressurized oil is discharged, with Figure 3A showing the XX cross-section and Figure 3B showing the YY cross-section. Figure 4 shows a cross-section of the mold pushing device 100 when pressurized oil is supplied, with Figure 4A showing the XX cross-section and Figure 4B showing the YY cross-section.

[0021] In Figure 3A, the cylinder housing 30 is a hollow cylindrical shape and includes a fixed cylinder chamber 35 and a collar chamber 36 on the inside of the hollow cylinder housing 30 from the top. Inside the hollow cylinder housing 30 are a return spring 38, a fixed piston 42, a piston rod 41, and necessary sealing members. The fixed piston 42 is fixed to the outer circumferential surface of the upper end of the piston rod 41. The lower end of the piston rod 41 is connected to the T-leg 40 through the collar chamber 36. The space between the collar chamber 36 and the piston rod 41 is sealed. A cap 37 closes the opening from the top of the fixed cylinder chamber 35, and the return spring 38 is positioned between the cap 37 and the fixed piston 42. The return spring 38 biases the fixed piston 42 downward. Pressurized oil from the hydraulic port 31 is introduced into the fixed cylinder chamber 35 from the passage 32 below the fixed piston 42.

[0022] The push housing 50 is a hollow cylindrical shape, and the inside of this hollow is the push cylinder chamber 56. The push cylinder chamber 56 is a cavity extending in direction D. Within the push cylinder chamber 56, a shaft portion 53 extends concentrically from one end of the push housing 50 (left side in the drawing) to the other end (right side in the drawing). The shaft portion 53 is fixed to the push housing 50 at one end. The rear side of the pressing portion 51 (left side in the drawing) is continuous with a push piston 52, which has a base portion that extends concentrically between the push housing 50 and the shaft portion 53. The inside of the base portion of the push piston 52 is hollow. The shaft portion 53 is housed inside the hollow of the push piston 52, and a biasing member 54 is positioned between the shaft portion 53 and the push piston 52. The biasing member 54 biases the push piston 52 in the return direction (leftward). Pressurized oil is introduced into the push cylinder chamber 56 from the central passage 55 of the shaft portion 53. Additionally, a necessary sealing member is provided between the push cylinder chamber 56 and the base of the push piston 52.

[0023] In Figure 3B, a sequence valve is configured within the sequence valve housing 60, with a primary port 61, a primary chamber 62, a secondary chamber 64, and a secondary port 63 formed in sequence. The primary port 61 communicates with the hydraulic port 31 via a passage 33, and the pressure from the fixed cylinder chamber 35 is expressed in the primary chamber 62. The secondary port 63 communicates with the push cylinder chamber 56 via passages 34 and 55.

[0024] Cylindrical filters 65 and 66 are positioned between the primary side port 61 and the primary side chamber 62, and between the secondary side chamber 64 and the secondary side port 63. A main valve 73 is provided between the primary side chamber 62 and the secondary side chamber 64 to block them from communicating. The main valve 73 is biased in the closing direction by a pressure setting spring 69 via spring receivers 70 and 71 and an interlocking member 72, while being pressed in the opening direction by pressurized oil supplied from the primary side chamber 62 through the valve seat hole 76. As a result, when the pressing force of the pressurized oil supplied to the primary side chamber 62 through the primary side port 61 exceeds a predetermined pressure set by the biasing force of the pressure setting spring 69, the main valve 73 opens. Conversely, when the pressing force of the pressurized oil supplied to the valve seat hole 76 falls below the biasing force of the pressure setting spring 69, the main valve 73 closes. The biasing force of the pressure setting spring 69 can be adjusted by the pressure setting screw 67 and the lock nut 68 that fixes the position of the pressure setting screw 67.

[0025] Furthermore, a reverse passage 77 is provided at the center of the main valve 73, connecting the secondary chamber 64 and the primary chamber 62, and a valve opening spring 75 normally causes a check valve 74 to close the reverse passage 77. When the main valve 73 is closed, if the pressure in the primary chamber 62 falls below the pressure in the secondary chamber 64, the check valve 74 opens, and the pressurized oil in the secondary chamber 64 flows out into the primary chamber 62.

[0026] Next, we will explain the operation when pressurized oil is supplied, starting from the state when pressurized oil is being discharged. In Figure 3, when pressurized oil is supplied from the hydraulic port 31, pressurized oil is introduced into the fixed cylinder chamber 35 and the primary side chamber 62. On the fixed cylinder chamber 35 side, the pressurized oil causes the fixed piston 42 to start rising. While the fixed piston 42 is rising, the pressing force of the pressurized oil supplied to the primary side chamber 62 is less than the biasing force of the pressure setting spring 69, and the main valve 73 remains closed. Therefore, the pressing part 51 does not move.

[0027] In Figure 4, the fixing piston 42 rises, pulling up the T-leg 40, and the mold pushing device 100 is fixed when the T-leg 40 engages with the T-groove 16 of the bolster 10. At this time, the pressure in the primary chamber 62 increases. When the pressing force of the pressurized oil in the primary chamber 62 exceeds the biasing force of the pressure setting spring 69, the main valve 73 opens. The pressurized oil reaches the push cylinder chamber 56 via the secondary chamber 64 and secondary port 63, moving the pressing part 51 in direction D. When the pressing part 51 can no longer move, the pressure in the secondary chamber 64 increases to counteract the pressure in the primary chamber 62, and the main valve 73 closes.

[0028] To return from the state in Figure 4 to the state in Figure 3, the pressure of the external pressurized oil into the hydraulic port 31 is reduced. The return spring 38 causes the fixing piston 42 to descend, and the pressurized oil from the fixing cylinder chamber 35 is discharged from the hydraulic port 31. In the sequence valve housing 60, the pressure in the primary chamber 62 falls below the pressure in the secondary chamber 64, and the check valve 74 opens. The biasing member 54 causes the push piston 52 to retract, and the pressurized oil passes through the secondary chamber 64 and the primary chamber 62, and is discharged from the hydraulic port 31.

[0029] Figure 5 shows the process of fixing the mold M to the bolster 10 using the mold pressing device 100 of this embodiment. The lower mold M1 and the upper mold M2 (only the lower mold M1 is shown with a dashed line) are mounted on the pre-roller 14. The rear side (upper side in the drawing) of the lower mold M1 has two notched first and second engaging parts p and q. The first engaging part p is triangular in shape and mainly defines the position of the lower mold M1 in the left-right direction. The second engaging part q is rectangular in shape and mainly defines the position of the lower mold M1 in the depth direction. By engaging the first and second engaging parts p and q with the positioning pins 17 and 18, the lower mold M1 is mounted in the predetermined position on the bolster 10. When the lower die M1 is mounted on the pre-roller 14, the first and second engaging parts p and q and the positioning pins 17 and 18 are roughly facing each other, with slight misalignments in the left-right and rotational directions (rotational direction around a line perpendicular to the drawing). In the diagram, the lower die M1 is assumed to be mounted on the pre-roller 14, relatively correct in the rotational direction but slightly misaligned in the left-right direction.

[0030] The worker moves the mold M on the pre-roller 14 (with the upper mold M2 and lower mold M1 stacked on top of each other) onto the die lifter 12 (upper part of the figure). The mold M is pushed further inward. The positioning pin 17 comes into contact with the inclined surface of the first engagement part p (center of the figure). At this point, the mold M becomes difficult to move. The mold pushing device 100 is mounted in the T-groove 16, and the hydraulic port 31 is connected. When pressurized oil is supplied to the pressurized oil port 31, the T-leg 40 of the mold pushing device 100 first rises and engages with the T-groove 16 of the bolster 10. As the pressure in the fixing cylinder chamber 35 increases, the pressure in the primary side chamber 62, which is in communication with the fixing cylinder chamber 35, also increases on the sequence valve housing 60 side. When this exceeds the biasing force of the pressure setting spring 69, the main valve 73 opens. As a result, the pressing part 51 starts moving immediately after being fixed in the T-groove 16, pushing the mold M. The mold M moves while shifting from side to side due to the inclined surface of the first engaging part p. Then, when both the first and second engaging parts p and q engage with the positioning pins 17 and 18, the mold M is mounted in a predetermined position on the bolster 10 (lower part of the figure). After that, the die lifter 12 is lowered to mount the mold M directly onto the bolster 10, and the upper mold M2 is fixed to the slide 20 by the hydraulic clamp 21, and the lower mold M1 is fixed to the bolster 10 by the hydraulic clamp 21.

[0031] Thus, with the mold pressing device 100 of this embodiment, the process from fixing the mold into the T-groove 16 to moving the pressing unit 51 is performed automatically without any time loss, eliminating the need for skilled operators and allowing mold changes to be completed in a short time. Furthermore, only one connection to the hydraulic port 31 is required. Moreover, since the pressing unit 51 begins to move only after it has been firmly fixed into the T-groove 16 of the bolster 10, the mold pressing device 100 will not retract due to the weight of the mold M.

[0032] Furthermore, by simply reducing the pressure of the pressurized oil in the hydraulic port 31, the mold pressing device 100 is automatically released from the T-groove 16 and the pressing part 51 is pulled without delay, making it easy to remove the mold pressing device 100 from the T-groove 16. [Explanation of Symbols]

[0033] 1 Molding equipment 10 bolster 11 Hydraulic hoses 12 Dirifter 13 Balls 14 Pre-roller 15 Laura 16 T groove 17, 18 pins 19 holes 20 slides 21 Hydraulic Clamp 30 Cylinder Housing 31 Hydraulic Ports Aisles 32, 33, and 34 35 Fixed cylinder chamber 36 Color Room 37 Cap 38. Return spring 40 T legs 41 Piston Rod 42 Fixed piston 50 Push Housing 51 Pressing part 52 Push piston 53 Shaft 54. Biasing member 55 aisle 56 Push cylinder chamber 60 Sequence valve housing 61 Primary Port 62 Primary concubine 63 Secondary Ports 64 Secondary concubine 65, 66 Cylindrical filters 67 Pressure setting screw 68 Lock Nuts 69 Pressure setting spring 72 Interlocking member 73. Chief Inspector 74 Check valve 75. Valve opening spring 76 valve seat holes 77 Reverse flow path 100 mold pressing device

Claims

[Claim 1] A mold pressing device that is detachably attached to a T-groove on a table fixed within a molding apparatus, and presses a mold on the table in the longitudinal direction of the T-groove by a pressing part, A hydraulic port that receives pressurized oil from the outside, When pressurized oil is supplied from the hydraulic port to the fixing cylinder chamber, a fixing piston is provided that pulls up the T-leg and engages it with the T-groove. A sequence valve comprising a first side chamber and a second side chamber, wherein the pressure of the pressurized oil in the fixed cylinder chamber is transmitted to the first side chamber, and pressurized oil is supplied to the first side chamber from the hydraulic port, and the valve opens when the pressure in the first side chamber exceeds a predetermined pressure, A mold pushing device having a push piston that moves the pressing portion in the longitudinal direction of the T-groove when pressurized oil is supplied from the second side chamber to the push cylinder chamber.

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