JP2010214792A - Mold clamping apparatus and movable platen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the quality of a molded product. <P>SOLUTION: This mold clamping apparatus has a fixed platen, a toggle support, a tie bar, a movable platen 14 disposed to be freely advance/retreat along the tie bar and mounted with a movable die 16, and a toggle mechanism disposed between the toggle support and the movable platen 14. The movable platen 14 includes a die mounting part AR1 mounted with the movable die, and connection parts 83, 84 for connecting the movable platen 14 to the toggle mechanism. A groove 68 is formed between the connection parts 83, 84 and the die mounting part AR1. Since the connection parts 83, 84 are separated from the die mounting part AR1, when force generated by the toggle mechanism is transmitted to the connection parts 83, 84, the bearing pressure distribution of the die mounting part AR1 in the movable platen 14 can be made uniform to prevent the deformation of the movable die 16. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mold clamping device and a movable platen.

  Conventionally, in a molding machine, for example, an injection molding machine, a resin heated and melted in a heating cylinder is filled into a cavity space of a mold apparatus at a high pressure, cooled and solidified in the cavity space. A molded product is formed.

  For this purpose, the mold apparatus includes a fixed mold and a movable mold, and a mold closing device is operated to move the movable mold forward and backward, and to contact and separate from the fixed mold, thereby closing the mold. Clamping and mold opening are performed.

  The mold clamping device is installed between a fixed platen as a fixed-side mold holding member for attaching a fixed mold, a toggle support disposed opposite to the fixed platen, and between the fixed platen and the toggle support. A movable platen as a movable mold holding member for mounting the movable mold, and disposed between the toggle support and the movable platen. A toggle mechanism or the like for moving the movable mold forward and backward by moving the platen back and forth is provided (see, for example, Patent Document 1).

JP-A-8-174612

  However, in the conventional mold clamping device, the force generated by the toggle mechanism pushes the upper and lower ends of the movable platen toward the fixed platen, so that the movable platen is bent. Along with that, the movable mold is deformed, so that the quality of the molded product is deteriorated.

  An object of the present invention is to provide a mold clamping device and a movable platen that can solve the problems of the conventional mold clamping device and can improve the quality of a molded product.

  Therefore, in the mold clamping device of the present invention, the stationary platen to which the stationary mold is attached, the toggle support disposed so as to face the stationary platen, and the bridge between the stationary platen and the toggle support. A tie bar, a movable platen disposed so as to be movable back and forth along the tie bar, and having a movable mold attached thereto, and a toggle mechanism disposed in a telescopic manner between the toggle support and the movable platen.

  The movable platen includes a mold attachment part to which the movable mold is attached, and a connection part for connecting the movable platen and the toggle mechanism.

  Further, a groove is formed between the connecting portion and the mold mounting portion.

  According to the present invention, in the mold clamping device, the stationary platen to which the stationary mold is attached, the toggle support disposed so as to face the stationary platen, and the bridge between the stationary platen and the toggle support. A tie bar, a movable platen disposed so as to be movable back and forth along the tie bar, and having a movable mold attached thereto, and a toggle mechanism disposed in a telescopic manner between the toggle support and the movable platen.

  The movable platen includes a mold attachment part to which the movable mold is attached, and a connection part for connecting the movable platen and the toggle mechanism.

  Further, a groove is formed between the connecting portion and the mold mounting portion.

  In this case, since the groove formed between the connecting portion and the mold attaching portion separates the connecting portion and the die attaching portion, the force generated by the toggle mechanism is transmitted to the connecting portion. In addition, the surface pressure distribution of the mold mounting portion in the movable platen can be made uniform, and the movable mold can be prevented from being deformed.

  In addition, since the gap formed between the fixed mold and the movable mold can be reduced, the molding material enters the gap to form burrs, or the molding material leaks through the gap. Can be suppressed. As a result, the quality of the molded product can be improved.

It is a front view of the movable platen in the embodiment of the present invention. It is a figure which shows the principal part of the injection molding machine in embodiment of this invention. It is XX sectional drawing of FIG. It is YY sectional drawing of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, an injection molding machine as a molding machine will be described.

  FIG. 2 is a view showing a main part of the injection molding machine according to the embodiment of the present invention.

  In the figure, Fr is a frame for supporting the injection molding machine, 11 is a fixed platen as a first support member attached to the frame Fr by a fixed block 29 and as a first mold holding member, and 12 is A toggle support as a second support member and a base plate placed on the frame Fr and arranged to face the fixed platen 11, 13 is between the fixed platen 11 and the toggle support 12. A tie bar 14 as a connecting member erected on the second plate 14 is disposed between the fixed platen 11 and the toggle support 12 so as to be opposed to the fixed platen 11 and to be moved forward and backward along the tie bar 13. It is a movable platen as a mold holding member. Then, a fixed mold 15 as a first mold and a movable mold 16 as a second mold are attached to the fixed platen 11 and the movable platen 14 so as to face each other.

  The fixed mold 15 and the movable mold 16 constitute a mold apparatus 20. An injection device (not shown) is disposed adjacent to the fixed platen 11.

  The tie bars 13 are disposed at the four corners of the fixed platen 11, the toggle support 12 and the movable platen 14. The tie bar 13 includes a main body portion 18 and a through portion 19 having a diameter slightly smaller than that of the main body portion 18 at the end on the fixed platen 11 side, and a screw portion (not shown) is formed at the tip of the through portion 19. The Then, the through portion 19 is inserted into the through hole 32 from the front end surface side of the fixed platen 11, and the stepped portion between the main body portion 18 and the through portion 19 is applied to the inner peripheral edge of the through hole 32 on the front end surface. One end of the tie bar 13 can be attached to the toggle support 12 by screwing the screw portion protruding from the rear end face with the nut 33.

  A toggle mechanism 21 as a mold clamping force transmission device is disposed between the toggle support 12 and the movable platen 14. In the toggle mechanism 21, a mold clamping motor (not shown) as a mold clamping drive unit is provided. When the crosshead 22 is advanced and retracted between the toggle support 12 and the movable platen 14 by driving, the movable platen 14 is advanced and retracted along the tie bar 13, and the movable mold 16 contacts and separates from the fixed mold 15. Thereby, the mold closing, mold clamping and mold opening of the mold apparatus 20 are performed.

  The toggle mechanism 21 has a double toggle structure, and is disposed in parallel with each other on the front side and the back side in the drawing, that is, on the left and right sides of the toggle support 12 and the movable platen 14, and has the same structure. A pair of link mechanisms 30 are provided.

  Each of the link mechanisms 30 has a symmetrical structure with respect to the center position in the height direction, and can swing with respect to the cross head 22 at the cross head 22 and at the upper and lower ends of the cross head 22. Toggle levers 23a and 23b as first links supported on the upper and lower ends of the toggle support 12 and toggle levers 24a and 24b as second links supported so as to be swingable with respect to the toggle support 12 In addition, toggle arms 25a and 25b as third links supported swingably with respect to the movable platen 14 are provided at the upper and lower ends of the movable platen 14.

  Further, connecting portions 81 and 82 are arranged at the upper and lower ends of the toggle support 12, and connecting portions 83 and 84 are arranged side by side at the upper and lower ends of the movable platen 14, and the toggle support 12 is interposed via the connecting portions 81 and 82. And the toggle mechanism 21 are connected to the movable platen 14 and the toggle mechanism 21 via the connecting portions 83 and 84.

  The crosshead 22 and the toggle levers 23a and 23b are connected by the pin p1, the toggle levers 23a and 23b and the toggle levers 24a and 24b are connected by the pin p2, and the toggle levers 24a and 24b and the toggle arms 25a and 25b are connected by the pin p3. The connecting portions 81 and 82 and the toggle levers 24a and 24b are linked by the pin p4, and the connecting portions 83 and 84 and the toggle arms 25a and 25b are linked by the pin p5.

  A ball screw shaft (not shown) is rotatably supported with respect to the toggle support 12, and the ball screw shaft and a ball nut (not shown) attached to the cross head 22 are screwed together. In order to rotate the ball screw shaft, the mold clamping motor is attached to the side surface of the toggle support 12, and the rotation of the mold clamping motor is transmitted to the ball screw shaft.

  Therefore, when the mold clamping motor is driven to rotate the ball screw shaft, the rotational motion of the ball screw shaft is converted into the linear motion of the ball nut, and the cross head 22 is moved back and forth. That is, when the cross head 22 is advanced, the toggle mechanism 21 is extended, the movable platen 14 and the movable mold 16 are advanced, and mold closing and clamping are performed. At this time, a cavity space (not shown) is formed between the fixed mold 15 and the movable mold 16, and the cavity space is filled with a resin as a molding material injected by the injection device.

  The injection device includes a heating cylinder as a cylinder member, and a screw as an injection member that is rotatably and reciprocally disposed in the heating cylinder, and rotates or advances the screw. For example, a metering motor as a metering drive unit, an injection motor as an injection drive unit, and the like are provided. When the metering motor is driven and the screw is rotated during the metering process, the resin dissolved in front of the screw in the heating cylinder is accumulated, and during the injection process, the injection motor is driven and the screw is driven. When the is moved forward, the resin accumulated in front of the screw is injected from an injection nozzle attached to the front end of the heating cylinder, and is filled in the cavity space.

  When the resin in the cavity space is cooled and solidified, a molded product is formed. When the cross head 22 is retracted, the toggle mechanism 21 is bent and the movable platen 14 and the movable mold 16 are retracted. The mold is opened. At this time, an ejector pin (not shown) as a projecting member is projected from the movable mold 16, and the molded product attached to the movable mold 16 is dropped.

  The toggle support 12 is provided with a mold thickness adjusting device 31 in order to change the effective length of the tie bar 13 in accordance with the thickness of the mold device 20 when the mold device 20 is replaced. The

  In the present embodiment, a mold clamping motor is arranged to advance and retract the cross head 22. However, a mold clamping cylinder is arranged as a mold clamping drive unit, and the mold clamping cylinder is arranged. The crosshead 22 can be advanced and retracted by driving. In the present embodiment, the toggle mechanism 21 is arranged to advance and retract the movable platen 14 and the movable mold 16, but the mold clamping cylinder can be used without using the toggle mechanism 21. Thus, the movable platen 14 and the movable mold 16 can be directly advanced and retracted.

  The fixed platen 11, toggle support 12, tie bar 13, movable platen 14, toggle mechanism 21, nut 33, mold clamping motor and the like constitute a mold clamping device. In addition, the ball screw shaft and the ball nut constitute a ball screw as a motion direction converting portion, and the ball screw shaft constitutes a first conversion element, and the ball nut constitutes a second conversion element.

  Next, the movable platen 14 will be described.

  1 is a front view of a movable platen according to an embodiment of the present invention, FIG. 3 is a sectional view taken along line XX in FIG. 1, and FIG. 4 is a sectional view taken along line YY in FIG.

  In the figure, reference numeral 14 denotes a movable platen. The movable platen 14 is formed at the four corners of the main body portion 57 and the main body portion 57 so as to protrude toward the toggle support 12 (FIG. 2), and has a substantially cylindrical shape. A tie bar holding portion 53 having a shape, and connecting portions 83, 84 formed at the center portions of the upper end and the lower end of the main body portion 57 so as to protrude in pairs toward the toggle support 12, respectively. The movable platen 14 and the toggle mechanism 21 are connected by 84.

  The main body 57 includes a mold mounting surface s1 on the side facing the fixed platen 11 and a toggle mechanism connecting surface s2 on the side facing the toggle support 12, and a mold set on the mold mounting surface s1. The movable mold 16 is detachably attached to the attachment portion AR1. In addition, a through hole h1 is formed in the central portion of the main body 57 from the die mounting surface s1 to the toggle mechanism connecting surface s2 for allowing protruding elements such as an ejector rod and an ejector pin (not shown) to pass therethrough.

  A through hole 62 for allowing the tie bar 13 to pass through is formed in each of the tie bar holding portions 53, and connection holes 83a and 84a are formed at the distal ends of the connection portions 83 and 84. A toggle hole is formed in the connection holes 83a and 84a. The pin p5 for swingably supporting the arms 25a and 25b is provided.

  The left and right connecting portions 83 are disposed adjacent to each other at a predetermined distance, and a reinforcing portion 85 is integrally formed between the connecting portions 83 to reinforce each connecting portion 83. Similarly, the left and right connecting portions 84 are also arranged adjacent to each other at a predetermined distance, and a reinforcing portion 86 is integrally formed between the connecting portions 84 to reinforce each connecting portion 84.

  By the way, when the mold clamping device is operated to advance the movable platen 14 and the movable mold 16 and perform mold clamping with a predetermined mold clamping force, the force generated by the toggle mechanism 21 causes the upper end of the movable platen 14 and It is transmitted to the connecting portions 83 and 84 formed at the lower end, and the movable platen 14 is pushed toward the fixed platen 11. At this time, when the movable platen 14 is bent, the movable mold 16 is deformed and molded. The quality of the product will deteriorate.

  Therefore, in the vicinity of the outer peripheral edge of the main body portion 57 between the connecting portions 83, 84 and the mold attachment portion AR1 in the movable platen 14, in the present embodiment, outside the mold attachment portion AR1, and A groove 68 that draws an annular loop is formed as a force transmission restraining portion at a predetermined position inside each through hole 62.

  Note that when the groove 68 is formed by cutting or the like, the cost of the movable platen 14 is increased. Therefore, in this embodiment, the groove 68 is formed by casting, and a taper taper in which the groove width is gradually increased is formed on the side surface of the groove 68 from the bottom to the mold mounting surface s1.

  In this case, the groove 68 has a substantially regular octagonal shape, and is parallel to the upper edge of the main body portion 57 between the upper two through-holes 62 and extends between both ends of each connecting portion 83. When the movable platen 14 is viewed from the fixed platen 11 side, the lower edge portion m2 extending between the two lower through holes 62 and parallel to the lower edge of the main body portion 57 and extending between both ends of each connecting portion 84. The movable platen 14 is moved from the left side edge portion m3 extending parallel to the left edge of the main body portion 57 between the two left side through holes 62 and by the same distance as the upper edge portion m1 and the lower edge portion m2, and the fixed platen 11 side. The right edge m4 extending in parallel with the right edge of the main body 57 between the two through holes 62 on the right side when viewed, and extending the same distance as the upper edge m1 and the lower edge m2, the upper edge m1 And slanted connecting the left edge m3 The upper left inclined part m5, the upper edge m1 and the right edge m4 connected to each other and the upper right inclined part m6 extending obliquely and the lower edge m2 and the left edge m3 connected to each other obliquely. The lower left inclined part m7 which extends, and the lower right inclined part m8 which extends diagonally by connecting between the lower edge part m2 and the right edge part m4 are provided.

  The upper edge m1, the lower edge m2, the left edge m3, the right edge m4, the upper left inclined part m5, the upper right inclined part m6, the lower left inclined part m7, and the lower right inclined part m8 are substantially the same length. First to eighth groove portions having a thickness are configured. In addition, an edge formed along the upper edge, the lower edge, the left edge, and the right edge of the main body 57 by the upper edge m1, the lower edge m2, the left edge m3, and the right edge m4. A groove is formed, and an upper left edge part m5, an upper right inclination part m6, a lower left inclination part m7, and a lower right inclination part m8 make an upper edge part m1, a lower edge part m2, a left edge part m3, and a right edge part m4. Thus, in the present embodiment, an inclined groove formed at an angle of 45 [°] is configured.

  In the height direction, the center line of the upper edge portion m1 is positioned slightly below the center of the connection hole 83a, and the center line of the lower edge portion m2 is positioned from the center of the connection hole 84a. Slightly above.

  By the way, at the four corners of the main body portion 57, tie bar holding portions 53 that surround the respective through holes 62 are formed so as to protrude and the main body portion 57 is reinforced, so that deformation at the four corners of the movable platen 14 is suppressed, and the The influence given to the mold 16 is small.

Therefore, each depth of the upper left inclined portion m5, upper right inclined portion m6, lower left inclined portion m7, and lower right inclined portion m8 is defined as d1, and the upper edge portion m1, the lower edge portion m2, the left edge portion m3, and the right edge. When each depth of the part m4 is d2,
d1 <d2
The groove width w1 of the upper left inclined part m5, the upper right inclined part m6, the lower left inclined part m7, and the lower right inclined part m8, and the upper edge part m1, the lower edge part m2, the left edge part m3 and the right side. Each groove width w2 of the edge portion m4 is
w1 <w2
It is said.

  Therefore, since the four corners of the mold attachment portion AR1 having a rectangular shape can be brought close to each through hole 62, the area of the mold attachment portion AR1 can be increased.

  As described above, in the present embodiment, the connecting portions 83 and 84 and the mold mounting portion AR1 are separated by the groove 68 and separated in the force transmission system, and thus generated by the toggle mechanism 21. When the force is transmitted to the connecting portions 83 and 84, a portion outside the groove 68 in the main body portion 57, mainly a portion above the upper edge portion m1 and a portion below the lower edge portion m2, are deformed, and the movable platen The force transmitted to 14 is absorbed. Therefore, since the surface pressure distribution of the mold mounting portion AR1 in the movable platen 14 can be made uniform, the movable mold 16 can be prevented from being deformed.

  Further, since the gap formed between the fixed mold 15 and the movable mold 16 can be reduced, resin enters the gap to form burrs, or resin leakage occurs through the gap. Can be suppressed. Therefore, the quality of the molded product can be improved.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

11 Fixed platen 12 Toggle support 13 Tie bar 14 Movable platen 15 Fixed mold 16 Movable mold 21 Toggle mechanism 33 Nut 57 Body 68 Groove AR1 Mold mounting part

Claims (5)

(A) a stationary platen to which a stationary mold is attached;
(B) a toggle support disposed facing the fixed platen;
(C) a tie bar installed between the fixed platen and the toggle support;
(D) a movable platen disposed so as to be movable back and forth along the tie bar and having a movable mold attached thereto;
(E) having a toggle mechanism disposed in a telescopic manner between the toggle support and the movable platen;
(F) The movable platen includes a mold attaching portion to which the movable die is attached, and a connecting portion for connecting the movable platen and the toggle mechanism,
(G) A mold clamping device, wherein a groove is formed between the connecting portion and the mold mounting portion.   The mold clamping device according to claim 1, wherein the groove is an annular groove.   2. The mold clamping device according to claim 1, wherein the groove includes an edge groove formed along an edge of the movable platen, and an inclined groove connecting the edge grooves.   The mold clamping device according to claim 3, wherein the inclined groove is formed shallower than the edge groove. A fixed platen to which a fixed mold is attached, a toggle support disposed opposite to the fixed platen, a tie bar installed between the fixed platen and the toggle support, and disposed so as to be movable forward and backward along the tie bar. In a movable platen of a mold clamping device having a movable platen to which a movable mold is attached, and a toggle mechanism which is arranged to be stretchable between the toggle support and the movable platen,
(A) a mold attaching portion to which the movable die is attached, and a connecting portion for connecting the movable platen and the toggle mechanism;
(B) A movable platen characterized in that a groove is formed between the connecting portion and the mold mounting portion.

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