Magnetic Clamping Device

Abstract

To provide a magnetic clamp device which can be easily brought into a state capable of exhibiting a fall prevention function when attaching an object to be adsorbed.SOLUTION: A support member (20) horizontally protrudes from a top of a magnetic plate (7) of a magnetic clamp device. A projecting member (28) protrudes upward from a mold (9) as an object to be adsorbed and fixed to an adsorbing surface (8) of the magnetic plate (7). An engaging part (32) provided on the projecting member (28) can be received from below by an engaging part (27) provided on the support member (20). With the mold (9) adsorbed and fixed at a predetermined position on the adsorbing surface (8), the engaging part (32) is disposed above the engaging part (27) so as to face it with a predetermined gap therebetween.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a magnetic clamping device that magnetically adsorbs and fixes a mold or the like as an object to be adsorbed to the side wall of a base, for example, a fixed platen or a movable platen of an injection molding machine, and particularly relates to a magnetic clamping device having a function of preventing the mold or the like from falling off the magnetic clamping device.

Background Art

[0002] Conventionally, there is a magnetic clamping device having such a mold fall prevention function described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-018546). The prior art is configured as follows. A conventional magnetic clamping device having a mold fall prevention function is attached to the fixed platen and the movable platen of an injection molding machine. An adsorption surface is formed on the side wall of the housing of the magnetic clamping device, and a mold can be magnetically adsorbed on the adsorption surface. A guide groove having a T-shaped cross section is formed vertically from the upper end to near the center so as to open to the adsorption surface. An engaging protrusion having a T-shaped cross section projects from the side surface of the mold that abuts against the adsorption surface in a direction perpendicular to the side surface of the mold. The engaging protrusion can be inserted into the guide groove through an opening formed in the upper surface of the housing. When attaching the mold to the adsorption surface, first, the movable platen is moved to a position where the distance between the fixed platen and the movable platen is slightly wider than the width of the mold. A mold suspended by a crane is carried in from above between the fixed platen and the movable platen. Next, the engaging protrusion is inserted into the guide groove, and the engaging protrusion is received by a stopper formed on the lower end peripheral wall of the guide groove. Subsequently, the movable platen is moved toward the fixed platen, and after the mold is sandwiched between the fixed platen and the movable platen, the mold is adsorbed and fixed to the adsorption surface by the magnetic clamping device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above prior art has the following problems. In the above magnetic clamp device, since the guide groove is housed within the thickness of the housing of the magnetic clamp device and the peripheral wall of the guide groove needs to have rigidity capable of withstanding the load due to the self-weight of the mold, it has been difficult to set a large insertion gap between the engaging projection and the peripheral wall of the guide groove. For this reason, when the mold is being carried in, while inserting the mold suspended by a crane and swinging in a space formed between the fixed plate and the movable plate, which is slightly wider than the dimensions of the mold, the engaging projection is inserted into the narrow guide groove. At this time, it is necessary to work carefully so that the mold and the engaging projection do not collide with the fixed plate, the movable plate, or peripheral equipment and get damaged or worn. Therefore, it has been time-consuming to bring the mold into a state where the mold-falling prevention function can be exerted when attaching the mold to the magnetic plate. An object of the present invention is to provide a magnetic clamp device that can be easily brought into a state where the mold-falling prevention function can be exerted when attaching an object to be adsorbed.

Means for Solving the Problems

[0005] Magnetic plates 7 are provided on the side walls of the bases 2 and 3. An adsorption surface 8 is formed on the side wall of the magnetic plate 7. An object 9 to be adsorbed is magnetically adsorbed at a predetermined position on the adsorption surface 8. A first permanent magnet 15 is inserted into a housing hole 11 formed in the magnetic plate 7. A coil 13 is wound around the outer periphery of the first permanent magnet 15. A magnetic pole member 16 that abuts against the first permanent magnet 15 is constituted by a magnetic material. A second permanent magnet 17 is mounted between the outer peripheral surface of the magnetic pole member 16 and the inner peripheral surface of the housing hole 11. A support member 20 projects from above the base 2, 3 or the magnetic plate 7 in a direction intersecting the adsorption surface 8. A projecting member 28 projects upward from the object 9 to be adsorbed. The projecting member 28 has an engaging portion 32. The engaging portion 32 is configured to be able to be received from below by a locking portion 27 provided on the support member 20. With the object 9 to be adsorbed adsorbed and fixed at the predetermined position on the adsorption surface 8, the engaging portion 32 is arranged to face the locking portion 27 with a predetermined gap thereabove.

[0006] The present invention described above has the following operational effects. In the above-described magnetic clamp device, the support member protrudes from the upper part of the base or the upper part of the magnetic plate in a direction intersecting the adsorption surface. Further, a protruding member protrudes upward from the object to be adsorbed, and an engaging portion of the protruding member is configured to be receivable from below by a locking portion provided on the support member. Further, in a state where the object to be adsorbed is adsorbed and fixed at a predetermined position on the adsorption surface, the engaging portion faces the locking portion with a gap thereabove. Therefore, when attaching the object to be adsorbed to the magnetic plate, the object to be adsorbed can be carried in from above in a state where it is sufficiently separated horizontally from the magnetic plate so that the object to be adsorbed does not collide with the magnetic plate or the like. Further, when the object to be adsorbed and the base are relatively moved horizontally so as to approach each other, and the object to be adsorbed is disposed at a predetermined position on the magnetic plate, the engaging portion faces the locking portion with a gap thereabove. Therefore, the magnetic clamp device of the present invention can be easily attached to a predetermined position on the magnetic plate without causing the object to be adsorbed to collide with peripheral devices such as the base and causing wear or damage. As a result, since the engaging portion is disposed so as to face the locking portion with a gap thereabove, the function of preventing the object to be adsorbed from falling can be easily achieved.

[0007] The present invention preferably further includes the following configuration. For example, as shown in FIGS. 7 to 9, a receiving surface 40 is formed on the upper wall of the support member 20 so as to be inclined with respect to the horizontal direction and have a lower height as it approaches the adsorption surface 8. The locking portion 27 is provided on the receiving surface 40. A flange portion 31 protrudes from the tip of the protruding member 28 in the radial direction of the protruding member 28. The engaging portion 32 is provided on the lower wall of the flange portion 31.

[0008] In this case, when the object to be adsorbed, which is adsorbed and fixed at a predetermined position on the adsorption surface of the magnetic plate, is unintentionally detached from the adsorption surface, the object to be adsorbed is received by the magnetic plate via the flange portion of the protruding member and the receiving surface of the protruding member. The object to be adsorbed is moved along the receiving surface toward the adsorption surface side by its own weight, and the object to be adsorbed is adsorbed to the adsorption surface by the adsorption force of the magnetic clamp device. Therefore, it is possible to reliably prevent the object to be adsorbed from falling from the magnetic plate and being worn or damaged.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0010] FIGS. 1 to 6 show an embodiment of the present invention. The injection molding machine 1 of this embodiment includes a fixed platen (base) 2 and a movable platen (base) 3, and the movable platen 3 is moved closer to or away from the fixed platen 2 along four tie bars 4 by a drive mechanism (not shown). Magnetic clamp devices 5 and 6 are respectively mounted on the fixed platen 2 and the movable platen 3. The magnetic clamp device 5 on the fixed platen 2 side and the magnetic clamp device 6 on the movable platen 3 side have substantially the same configuration, and the structure thereof will be described with reference to FIGS. 1 and 6 based on the magnetic clamp device 5 on the fixed platen 2 side.

[0011] As shown in FIG. 1, a magnetic plate 7 as a housing of the magnetic clamp device 5 is made of a ferromagnetic material. An adsorption surface 8 is formed on the left side wall of the magnetic plate 7, and a mold 9 can be adsorbed and fixed to the adsorption surface 8. The mold (adsorption object) 9 includes a fixed mold 9a adsorbed and fixed to the magnetic clamp device 5 on the fixed platen 2 side and a movable mold 9b adsorbed and fixed to the magnetic clamp device 6 on the movable platen 3 side. When the mold 9 is suspended by a crane and carried into the injection molding machine 1, the fixed mold 9a and the movable mold 9b are connected by a fixing metal fitting 10.

[0012] As shown in FIG. 5, a plurality of accommodation holes 11 are formed in the magnetic plate 7 so as to open to the adsorption surface 8. A permanent magnet 12 is inserted so as to abut against the bottom wall of each accommodation hole 11. The permanent magnet 12 includes a ring-shaped bobbin 14 around which a plurality of coils 13 are wound and a cylindrical first permanent magnet 15 inserted into the cylindrical hole of the bobbin 14. The first permanent magnet 15 is made of a neodymium magnet. Further, a cylindrical magnetic pole member 16 is inserted into the accommodation hole 11 so as to abut against the first permanent magnet 15. The magnetic pole member 16 is made of a ferromagnetic material. A housing groove is formed in the circumferential direction on the outer peripheral wall of the magnetic pole member 16, and a second permanent magnet 17 is mounted in the housing groove. The second permanent magnet 17 is made of an alnico magnet.

[0013] As shown in FIGS. 1 and 5, a plurality of coils 13 are connected by a wiring 18, and the wiring 18 is connected to a magnetic control device 19. The magnetic control device 19 is composed of a computer including a CPU, a ROM, and a RAM and a power supply unit (not shown) that supplies power to the coil 13. The magnetic control device 19 switches between a state where the magnetic plate 7 adsorbs the mold 9 and a state where the adsorption is released.

[0014] As shown in FIGS. 1 and 6, a support member 20 projects from the upper part of a magnetic plate 7 of a magnetic clamp device 5 attached to the above-mentioned fixing plate 2 in a direction intersecting the adsorption surface 8 (hereinafter referred to as the intersecting direction). The support member 20 is fixed to the magnetic plate 7 by bolts 22. An insertion hole 23 is formed in the support member 20 to extend in the intersecting direction so as to open at the left end surface of the support member 20. The support member 20 includes a base portion 24 attached to the magnetic plate 7 and two receiving portions 25 projecting horizontally from the base portion 24 so as to sandwich the insertion hole 23. A protrusion 26 projects upward from the tip of the receiving portion 25. A locking portion 27 is formed on the upper surface of the receiving portion 25.

[0015] A female screw hole is formed in the vertical direction in the upper part of the above-mentioned mold 9, and the main body portion 30 of the protruding member 28 is screwed into the female screw hole so that the height can be adjusted. The main body portion 30 is fixed to the mold 9 by a nut at the adjusted height position. Thus, the main body portion 30 of the round bar-shaped protruding member 28 projects from the upper end surface of the mold 9 so that the height can be adjusted. A flange portion 31 projects from the tip portion in the radial direction of the main body portion 30. An engaging portion 32 is formed on the lower surface of the flange portion 31. The main body portion 30 is configured to be insertable into the insertion hole 23 of the support member 20, and the engaging portion 32 of the flange portion 31 is configured to be able to receive the locking portion 27 of the receiving portion 25 from below.

[0016] When attaching the mold 9 between the fixed platen 2 and the movable platen 3 of the injection molding machine 1, first, as shown in FIGS. 1 and 2, in the mold-open state of the injection molding machine 1 where the movable platen 3 is sufficiently separated from the fixed platen 2, the mold 9 suspended by the crane is carried in from above into the space formed between the fixed platen 2 and the movable platen 3. Next, the operator moves the mold 9 horizontally toward the magnetic plate 7 by operating the crane or manually, and as shown in FIG. 3, the locating ring 35 attached to the side wall of the mold 9 is inserted into the guide hole 36 formed in the center of the magnetic plate 7 on the fixed platen 2 side. At this time, the main body portion 30 of the protruding member 28 provided on the fixed mold 9a of the mold 9 is inserted into the insertion hole 23 of the support member 20 of the fixed platen 2. Also, at this time, since the lower surface (engaging portion) of the flange portion 31 of the protruding member 28 is at a position higher by a height H than the upper surface of the protruding portion 26 of the support member 20, the protruding portion 26 of the support member 20 is prevented from colliding with the flange portion 31 of the protruding member 28. Subsequently, when the operator rotates and moves the mold 9 around the central axis of the guide hole 36 for position adjustment, the mold 9 is arranged at a predetermined position on the magnetic plate 7. Next, when the movable platen 3 is moved toward the fixed platen 2, as shown in FIG. 4, the mold 9 is clamped by the fixed platen 2 and the movable platen 3. At this time, the main body portion 30 of the protruding member 28 fixed to the movable mold 9b of the mold 9 is inserted into the insertion hole 23 of the support member 20 attached to the movable platen 3. Also, at this time, since the engaging portion 32 of the flange portion 31 of the protruding member 28 is at a position higher by a height H than the upper surface of the protruding portion 26 of the support member 20, the protruding portion 26 of the support member 20 is prevented from colliding with the flange portion 31 of the protruding member 28. Thereafter, the operator operates the magnetic control device 19 to adsorb and fix the mold 9 to the magnetic plate 7 by the magnetic clamping devices 5 and 6.

[0017] When the fixed die 9a of the die 9 magnetically fixed to the above-described magnetic clamp device 5 or the movable die 9b magnetically fixed to the clamp device 6 is inadvertently separated from the magnetic clamp devices 5 and 6 for some reason, the fixed die 9a or the movable die 9b moves downward due to its own weight and is received by the magnetic clamp devices 5 and 6 via the locking portion 27 of the protruding member 28 and the engaging portion 32 of the support member 20. Thereby, it is possible to prevent the die 9 from falling from the injection molding machine 1 and being damaged.

[0018] The above-described embodiment has the following advantages. The support member 20 protrudes from the upper part of the clamp device 5 on the fixed platen 2 side and from the upper part of the clamp device 6 on the movable platen 3 side in a direction intersecting the adsorption surface 8, respectively. Further, the protruding member 28 protrudes upward from the die 9 and is configured to be received from below by the support member 20. Further, in a state where the die 9 is adsorbed and fixed at a predetermined position on the adsorption surface 8, the engaging portion 32 faces the locking portion 27 with a gap thereabove. For this reason, when attaching the die 9 to the magnetic plate 7, the die 9 can be carried in from above in a state where it is sufficiently separated horizontally from the magnetic plate 7 so that the die 9 does not collide with the magnetic plate 7 or the like. Further, by relatively moving the fixed die 9a horizontally toward the fixed platen 2 or moving the movable platen 3 closer to the movable die 9b and arranging the die 9 at a predetermined position on the magnetic plate 7, the engaging portion 32 faces the locking portion 27 with a gap thereabove. Therefore, the magnetic clamp devices 5 and 6 of the present invention can attach the die 9 to a predetermined position on the magnetic plate 7 without the die 9 colliding with peripheral devices such as the fixed platen 2 or the movable platen 3 and being worn or damaged. As a result, since the engaging portion 32 is arranged to face the locking portion 27 with a gap thereabove, the die drop prevention function can be easily brought into a state where it can be exhibited.

[0019] Figs. 7 to 9 show a modification of the above-described embodiment. In this modification, the same members (or similar members) as the constituent members of the above-described embodiment are basically denoted by the same reference numerals for description. The differences between this modification and the above-described embodiment are as follows.

[0020] As shown in Fig. 7, in the magnetic clamp device 5 of the above modification example, a receiving surface 40 is formed on the upper wall of the receiving portion 25 so as to be inclined (downward to the right) with respect to the horizontal direction. Thereby, when the mold 9 adsorbed and fixed to the magnetic clamp devices 5 and 6 is unintentionally detached for some reason, the engaging portion 27 of the flange portion 31 of the protruding member 28 of the mold 9 is received by the locking portion 27 formed on the receiving surface 40 of the support member 20A. Thereafter, the mold 9 is moved toward the magnetic plate 7 side along the receiving surface 40 by its own weight, and the mold 9 approaches the magnetic plate 7. As a result, the mold 9 once separated from the magnetic clamp device 5 is supported by the magnetic clamp device 5 by the protruding member 28 and the support member 20, and is again adsorbed and fixed to the adsorption surface 8 by the magnetic force of the magnetic clamp device 5. As a result, it is possible to reliably prevent the mold 9 separated from the magnetic clamp device 5 from falling and being worn or damaged.

[0021] Also, as shown in FIGS. 7 to 9, a pivot support portion 29 of the protruding member 28 is provided upward from the upper end surface of the mold 9, and the main body portion 30 of the protruding member 28 is pin-connected to the pivot support portion 29 so as to be rotatable. The main body portion 30 is formed in a rod shape, and a flange portion 31 protrudes from the tip end portion in the radial direction of the main body portion 30. An engaging portion 32 is formed on the lower surface of the flange portion 31. The main body portion 30 is configured to be insertable into the insertion hole 23 of the support member 20, and the engaging portion 32 of the flange portion 31 is configured to be receivable from below by the locking portion 27 of the receiving portion 25. Further, a cylindrical member 33 is externally fitted to the main body portion 30 so as to be movable along the outer peripheral surface of the main body portion 30. Further, by moving the cylindrical member 33 to the lower limit position, the cylindrical member 33 can externally fit the main body portion 30 and the pivot support portion 29 at once. For this reason, as shown in FIG. 8, when the cylindrical member 33 is moved to the upper limit position and the cylindrical member 33 is externally fitted only to the main body portion 30, the main body portion 30 can be rotated with respect to the pivot support portion 29. Further, as shown in FIG. 7, when the cylindrical member 33 is externally fitted to the main body member 30 and the pivot support portion 29, the rotation of the main body portion 30 with respect to the pivot support portion 29 is restricted, and the main body portion 30 is maintained in a state of protruding upward from the upper surface of the mold 9. Therefore, when the mold 9 is not used, as shown in FIG. 9, the support member 20 can be rotated and folded. Thereby, when storing the unused mold 9 in a storage shelf (not shown) or the like, the mold 9 can be made compact and easily stored, and it is possible to prevent the protruding member 28 from coming into contact with peripheral equipment or the like and wearing or being damaged.

[0022] Each of the above embodiments can be modified as follows. The above-described object to be adsorbed is not limited to the exemplified mold 9, and may be a workpiece or the like. The above-described support member 20 is not limited to protruding from the upper part of the magnetic plate 7 by only one, and may be provided in plurality. In this case, all or some of the plurality of support members 20 support the protruding member 28 of the mold 9. Also, it is not limited to supporting one protruding member 28 by one support member 20, and one protruding member 28 may be supported by a plurality of support members 20, or a plurality of protruding members 28 may be supported by one support member 20. Further, the support member 20 is not limited to being bolted to the upper part of the magnetic plate 7, and may be fixed to the fixed plate 2 or the movable plate 3. Instead of the receiving portion 25 and the protruding portion 26 of the above-described support member 20 being integrally formed, the receiving portion 25 and the protruding portion 26 may be formed as separate members. In this case, the protruding portion 26 is attached to the receiving portion 25 via a leaf spring member, and the leaf spring biases the protruding portion 26 toward the adsorption surface 8 with respect to the receiving portion 25. Thereby, when the protruding portion 26 receives the protruding member 28 of the mold 9, the protruding member 28 is pushed toward the adsorption surface 8 via the protruding portion 26 by the biasing force of the leaf spring. As a result, the chance of the mold 9 being adsorbed to the magnetic plate 7 again increases. Of course, various modifications can be made within the scope that those skilled in the art can assume.

Explanation of Reference Numerals

[0023] 2: Base plate 2, 3: Base plate, 7: Magnetic plate, 8: Adsorption surface, 9: Mold (object to be adsorbed), 11: Accommodation hole, 13: Coil, 15: First permanent magnet, 16: Magnetic pole member, 17: Second permanent magnet, 20: Support member, 27 Locking portion, 28: Protruding member, 31: Flange portion, 32: Engaging portion, 40: Receiving surface.

Claims

1. A magnetic plate (7) provided on the side wall of a base (2, 3); An adsorption surface (8) formed on the side wall of the magnetic plate (7), which adsorbs an object to be adsorbed (9) magnetically at a predetermined position on the adsorption surface (8); A first permanent magnet (15) inserted into a receiving hole (11) formed in the magnetic plate (7); A coil (13) wound around the outer periphery of the first permanent magnet (15); A magnetic pole member (16) which abuts against the first permanent magnet (15) and is composed of a magnetic material; A second permanent magnet (17) mounted between the outer peripheral surface of the magnetic pole member (16) and the inner peripheral surface of the receiving hole (11); A support member (20) projecting in a direction intersecting the adsorption surface (8) from above the base (2, 3) or the magnetic plate (7); A projecting member (28) projecting upward from the object to be adsorbed (9) and having an engaging portion (32) configured to be received from below by a locking portion (27) provided on the support member (20); With the object to be adsorbed (9) adsorbed and fixed at the predetermined position on the adsorption surface (8), the engaging portion (32) is arranged to face the locking portion (27) with a predetermined gap above it; And the main body portion (30) of the projecting member (28) is screwed into a female screw hole formed vertically in the upper part of the object to be adsorbed (9), and the flange portion (32) of the projecting member (28) projects in the radial direction of the main body portion (30) from above, whereby the flange portion (32) provides the engaging portion (32). Further, The support member (20) has two receiving portions (25) projecting horizontally beyond the adsorption surface (8), and the main body portion (30) can be inserted into the space sandwiched between the two receiving portions (25). The locking portion (27) is formed on the upper surface of the receiving portion (25). A magnetic clamping device characterized by this.

2. In the magnetic clamping device according to Claim 1, The receiving surface (40) on the upper wall of the support member (20) is inclined with respect to the horizontal direction and is formed such that the height decreases as it approaches the adsorption surface (8); The locking portion (27) is provided on the receiving surface (40); A flange portion (31) projects in the radial direction of the projecting member (28) from the tip of the projecting member (28); A magnetic clamp device, characterized in that the engaging portion (32) is provided on the lower wall of the flange portion (31).

Images