Fixed platen and mold clamping device

Abstract

The present disclosure pertains to a fixed platen provided to a mold clamping device that opens / closes a mold in a direction in which a tie bar extends. The fixed platen comprises: a body to which the mold is attached; a protruding part which protrudes from the body in a first direction intersecting the opening / closing direction of the mold and in which a first insertion hole into which the tie bar is inserted is formed; and a fixing part that is connected to the protruding end of the protruding part, that has the end of the tie bar fixed thereto, and that has formed therein a second insertion hole into which the tie bar is inserted. The fixing part is supported on the protruding part so as to be freely displaceable with respect to the body.

Description

Fixed platen and clamping unit

[0001] The present disclosure relates to a stationary platen and a mold clamping device.

[0002] A mold clamping device that opens and closes a mold along the direction in which tie bars extend is known. The mold clamping device is equipped with a stationary platen. JP 2015-150693 A discloses a stationary platen that improves the surface pressure distribution at the mold parting surface without increasing the weight of the platen. This stationary platen has a mold mounting portion (main body portion), a tie bar support portion that is installed spaced apart from the mold mounting portion and to which tie bars can be fixed, and a load transmission portion that connects the mold mounting portion and the tie bar support portion.

[0003] When the mold clamping device clamps the mold and a clamping force is applied to the mold, excessive distortion tends to occur in the tie bars, and there is a demand for reducing such distortion.

[0004] A first aspect of the present disclosure is a fixed platen provided in a mold clamping device that opens and closes a mold along the direction in which a tie bar extends, the fixed platen comprising: a main body to which the mold is attached; a protruding portion that protrudes from the main body in a first direction intersecting the opening and closing direction of the mold and has a first insertion hole through which the tie bar is inserted; and a fixed portion that is connected to the protruding end of the protruding portion and has a second insertion hole through which the tie bar is inserted and to which an end of the tie bar is fixed, the fixed portion being supported by the protruding portion so as to be freely displaceable relative to the main body.

[0005] A second aspect of the present disclosure is a mold clamping device comprising: a fixed platen of the first aspect; a rear platen arranged at a distance from the fixed platen; a tie bar having one end fixed to the fixed platen and the other end fixed to the rear platen; and a movable platen arranged to be movable along the tie bar.

[0006] Fig. 1 is an external view showing a mold clamping device in one embodiment. Fig. 2 is a partial front view of a fixed platen. Fig. 3 is a partial cross-sectional view of the mold clamping device taken along line III-III in Fig. 2. Fig. 4 is a schematic diagram showing a state of a mold clamping device in a comparative example during mold clamping. Fig. 5 is a schematic diagram showing a state of a mold clamping device in one embodiment during mold clamping. Fig. 6 is an external view showing a mold clamping device in a modified example. Fig. 7 is a schematic diagram showing a state of a mold clamping device in a modified example during mold clamping.

[0007] When a mold clamping force is applied to a mold, a reaction force of the mold clamping force is generated in the stationary platen. When a reaction force of the mold clamping force is generated in the stationary platen, a force (bending force) that tries to bend the tie bar acts on the tie bar through the portion where the tie bar is fixed, and the tie bar may be excessively distorted. Excessive distortion of the tie bar leads to deformation of the tie bar. The present disclosure proposes a stationary platen and a mold clamping device that can suppress deformation of the tie bar.

[0008] 1 is an external view showing a mold clamping apparatus 10 according to one embodiment. The mold clamping apparatus 10 is an apparatus that opens and closes a mold 12 and applies a mold clamping force to the closed mold 12. The mold clamping apparatus 10 includes the mold 12, a fixed platen 14, a rear platen 16, a movable platen 18, tie bars 20, and a mold clamping drive unit 22.

[0009] The mold 12 is disposed between a fixed platen 14 and a movable platen 18. The mold 12 is formed so as to be able to open and close. The mold 12 has a fixed mold 120 and a movable mold 122. The fixed mold 120 is attached to the fixed platen 14. The movable mold 122 is attached to the movable platen 18. When the mold 12 is in the open state, the fixed mold 120 and the movable mold 122 are separated from each other. When the mold 12 is in the closed state, the fixed mold 120 and the movable mold 122 are in contact with each other.

[0010] The fixed platen 14 and the rear platen 16 are installed on the stand 24 with a gap between them in the opening / closing direction D1 of the mold 12. A through-hole 14H is formed in the fixed platen 14. The through-hole 14H passes through the fixed platen 14 along the opening / closing direction D1 of the mold 12. A nozzle of an injection device (not shown) can be inserted into the through-hole 14H.

[0011] The movable platen 18 is disposed between the stationary platen 14 and the rear platen 16. The movable platen 18 is movably attached to guide rails 26. The guide rails 26 are installed on the stand 24 along the opening / closing direction D1 of the mold 12. Therefore, the movable platen 18 is movable in the opening / closing direction D1 of the mold 12. The direction in which the movable platen 18 approaches the stationary platen 14 is the closing direction D10 of the opening / closing direction D1 of the mold 12. Conversely, the direction in which the movable platen 18 moves away from the stationary platen 14 is the opening direction D11 of the opening / closing direction D1 of the mold 12.

[0012] The tie bars 20 extend along the opening / closing direction D1 of the mold 12. A plurality of tie bars 20 are provided at intervals from one another. One end of each tie bar 20 is fixed to the stationary platen 14 by a fastening member 28 such as a lock nut. The other end of each tie bar 20 is fixed to the rear platen 16 by a fastening member 28. Each of the plurality of tie bars 20 penetrates the movable platen 18. The movable platen 18 is guided by the plurality of tie bars 20 when it moves in the opening / closing direction D1 of the mold 12.

[0013] In this embodiment, two upper tie bars 20A and two lower tie bars 20B are provided, but the number is not limited to this. The two upper tie bars 20A and the two lower tie bars 20B are arranged parallel to each other at an interval in the width direction D2 of the mold clamping unit 10.

[0014] The mold clamping drive unit 22 moves the movable platen 18 forward and backward relative to the fixed platen 14 to open and close the mold 12. The mold clamping drive unit 22 has an extension / retraction mechanism 34. The extension / retraction mechanism 34 is, for example, a toggle mechanism. The extension / retraction mechanism 34 is attached to the rear platen 16 and the movable platen 18. The extension / retraction mechanism 34 is extended and retracted by driving a motor (not shown).

[0015] In response to the extension of the telescopic mechanism 34, the movable mold 122 attached to the movable platen 18 moves in the closing direction D10. In response to this movement, the movable mold 122 comes into contact with the fixed mold 120, and the mold 12 enters a closed state. When the mold 12 closes, a cavity is formed inside the mold 12. After the movable mold 122 comes into contact with the fixed mold 120, the mold clamping drive unit 22 applies a mold clamping force to the mold 12.

[0016] In response to the contraction of the telescopic mechanism 34, the movable mold 122 attached to the movable platen 18 moves in the opening direction D11. In response to this movement, the movable mold 122 moves away from the stationary mold 120, and the mold 12 enters an open state. When the movable platen 18 moves away from the stationary platen 14 to a position separated by a predetermined distance, the contraction of the telescopic mechanism 34 stops.

[0017] Fig. 2 is a partial front view of the stationary platen 14. The stationary platen 14 is symmetrical with respect to a horizontal line LN passing through the center of the stationary platen 14 as the axis of symmetry, but is not limited to this. Fig. 3 is a partial cross-sectional view of the mold clamping unit 10 taken along line III-III in Fig. 2. Fig. 3 shows the upper part above the horizontal line LN. Fig. 3 also shows only a portion of the stationary platen 14 and the movable platen 18 in cross section.

[0018] 3, the stationary platen 14 has a main body portion 140, a protruding portion 142, a fixing portion 144, and a tie bar support portion 146. One protruding portion 142, one fixing portion 144, and one tie bar support portion 146 are provided for each tie bar 20. Note that one protruding portion 142, one fixing portion 144, and one tie bar support portion 146 may be provided for each of the two upper tie bars 20A or the two lower tie bars 20B.

[0019] The main body 140 has a first surface 150 and a second surface 152. The first surface 150 is the surface to which the fixed mold 120 is attached. The second surface 152 is the surface opposite to the first surface 150. A through hole 14H is formed in the main body 140. The through hole 14H penetrates the main body 140 from the first surface 150 to the second surface 152.

[0020] The protruding portion 142 is formed integrally with the main body portion 140. The protruding portion 142 may be a separate body from the main body portion 140. In this case, the protruding portion 142 is attached to the main body portion 140 by welding or the like.

[0021] The protruding portion 142 is located between the fixing portion 144 and the tie bar support portion 146. The protruding portion 142 protrudes from the main body portion 140 toward the tie bar 20. A protruding direction (first direction) D20 of the protruding portion 142 is a direction intersecting with the opening / closing direction D1 of the mold 12. More specifically, when the first surface 150 is the front surface and the second surface 152 is the rear surface, the protruding direction D20 of the protruding portion 142 is a diagonal rearward direction.

[0022] The protruding portion 142 is inclined with respect to the opening / closing direction D1 of the mold 12. More specifically, the protruding portion 142 is inclined so that the amount of protrusion from the main body portion 140 increases the closer it is to the second surface 152 of the main body portion 140. A distance DT1 between the protruding end E1 of the protruding portion 142 and the first surface 150 of the main body portion 140 in the opening / closing direction D1 of the mold 12 is greater than a distance DT2 between the base end E2 of the protruding portion 142 and the first surface 150 of the main body portion 140 in the opening / closing direction D1 of the mold 12.

[0023] The protrusion 142 has an insertion hole (first insertion hole) 142H formed therein, through which the tie bar 20 is inserted. A bearing may be provided between the tie bar 20 and the inner surface of a portion of the protrusion 142 that surrounds the insertion hole 142H.

[0024] The fixing portion 144 is formed integrally with the protruding portion 142. The fixing portion 144 may be separate from the protruding portion 142. In this case, the fixing portion 144 is attached to the protruding portion 142 by welding or the like.

[0025] The fixed portion 144 is connected to the protruding end E1 of the protruding portion 142. The fixed portion 144 extends from the protruding end E1 of the protruding portion 142 toward the main body portion 140. The extension direction D21 of the fixed portion 144 is a direction intersecting the opening / closing direction D1 of the mold 12. More specifically, the extension direction D21 is a direction approximately perpendicular to the opening / closing direction D1 of the mold 12 and is different from the protruding direction D20 of the protruding portion 142.

[0026] The fixed portion 144 has an insertion hole (second insertion hole) 144H formed therein, through which the tie bar 20 is inserted. A bearing may be provided between the tie bar 20 and the inner surface of a portion of the fixed portion 144 that surrounds the insertion hole 144H. An end (one end) of the tie bar 20 that is inserted into the insertion hole 144H of the fixed portion 144 is fixed to the fixed portion 144 by a fastening member 28.

[0027] The fixed portion 144 is supported by the protruding portion 142 so as to be displaceable relative to the main body portion 140. More specifically, the fixed portion 144, excluding the portion of the fixed portion 144 supported by the protruding portion 142, is separated from the main body portion 140 and the protruding portion 142 by a space.

[0028] In other words, not only are the main body 140 and the fixed portion 144 separated from each other, but a portion of the protruding portion 142 and a portion of the fixed portion 144 are also separated from each other. In other words, the portion of the protruding portion 142 through which the tie bar 20 is inserted and the portion of the fixed portion 144 through which the tie bar 20 is inserted face each other across a space. As a result, a gap GP1 is formed between the protruding portion 142 and the fixed portion 144. Therefore, the protruding portion 142 is more likely to deform than when the protruding portion 142 and the fixed portion 144 are integrally formed without the gap GP1. In response to the deformation of the protruding portion 142, the fixed portion 144 is displaced in the opening / closing direction D1 of the mold 12.

[0029] The tie bar support portion 146 protrudes from the main body portion 140 toward the tie bar 20. The protruding direction (second direction) D22 of the tie bar support portion 146 is a direction intersecting the opening / closing direction D1 of the mold 12. More specifically, the protruding direction D22 is a direction approximately perpendicular to the opening / closing direction D1 of the mold 12, and is the opposite direction to the extension direction D21 of the fixing portion 144.

[0030] The tie bar support portion 146 has an insertion hole (third insertion hole) 146H formed therein, through which the tie bar 20 is inserted. A bearing (not shown) is provided between the tie bar 20 and the inner surface of a portion of the tie bar support portion 146 that surrounds the insertion hole 146H. The tie bar support portion 146 supports the tie bar 20 via this bearing. Note that a bearing need not be provided. In this case, the tie bar support portion 146 can support the tie bar 20 in a manner that suppresses deformation of the tie bar 20.

[0031] The tie bar support portion 146 is separated from the protrusion 142 by a space. In other words, the portion of the tie bar support portion 146 through which the tie bar 20 is inserted and the portion of the protrusion 142 through which the tie bar 20 is inserted face each other across a space. Therefore, a gap GP2 is formed between the tie bar support portion 146 and the protrusion 142.

[0032] The movable platen 18 has a main body portion 180, a connecting portion 182, and a tie bar support portion 184. One connecting portion 182 and one tie bar support portion 184 are provided for each tie bar 20. Note that one connecting portion 182 and one tie bar support portion 184 may be provided for each of the two upper tie bars 20A or the two lower tie bars 20B.

[0033] The main body 180 has a first surface 190 and a second surface 192. The first surface 190 is the surface to which the movable mold 122 is attached. The second surface 192 is the surface opposite to the first surface 190.

[0034] The connecting portion 182 is a portion that connects the main body portion 180 and the extension / retraction mechanism 34. The connecting portion 182 is formed integrally with the main body portion 180. The connecting portion 182 may be a separate body from the main body portion 180. In this case, the connecting portion 182 is attached to the main body portion 180 by welding or the like.

[0035] The connecting portion 182 extends from the main body 180 toward the tie bar 20. A link of the extension mechanism 34 is connected to the tip portion of the connecting portion 182. An insertion hole 182H, through which the tie bar 20 is inserted, is formed between the main body 180 and the tip portion of the connecting portion 182 to which the link of the extension mechanism 34 is connected.

[0036] The tie bar support portion 184 protrudes from the main body portion 180 toward the tie bar 20. The protruding direction of the tie bar support portion 184 is the same as the protruding direction D22 of the tie bar support portion 146.

[0037] The tie bar support portion 184 has an insertion hole 184H formed therein, through which the tie bar 20 is inserted. A bearing (not shown) is provided between the tie bar 20 and the inner surface of the portion of the tie bar support portion 184 that surrounds the insertion hole 184H. The tie bar support portion 184 supports the tie bar 20 via this bearing. As with the tie bar support portion 146, a bearing does not necessarily have to be provided.

[0038] The tie bar support portion 184 is separated from the connecting portion 182 by a space. In other words, the portion of the tie bar support portion 184 through which the tie bar 20 is inserted and the portion of the connecting portion 182 through which the tie bar 20 is inserted face each other across a space. Therefore, a gap GP3 is formed between the tie bar support portion 184 and the connecting portion 182.

[0039] Fig. 4 is a schematic diagram showing the state during mold clamping of the mold clamping unit 100 in the comparative example. In Fig. 4, the same components as those described in the above embodiment are assigned the same reference numerals. The mold clamping unit 100 in the comparative example is provided with a load transmission block 200 instead of the protruding portion 142 and the fixing portion 144 of the present embodiment.

[0040] The load transmission block 200 is a solid block in which no gap GP1 is formed. The load transmission block 200 extends from the main body 140 toward the tie bar 20. An insertion hole (not shown) through which the tie bar 20 is inserted is formed in the load transmission block 200. An end (one end) of the tie bar 20 inserted into this insertion hole is fixed to the load transmission block 200 by a fastening member 28. A gap GP4 is formed between the load transmission block 200 and the tie bar support portion 146.

[0041] In the movable platen 18 of the comparative example, a gap GP3 is formed between the connecting portion 182 and the tie bar support portion 184. Therefore, even if a clamping force is applied to the mold 12 via the movable platen 18 by the extension / contraction mechanism 34, the variation in the load applied to the movable mold 122 is reduced compared to when the gap GP3 is not formed.

[0042] On the other hand, when a clamping force is applied to the mold 12 via the movable platen 18 by the telescopic mechanism 34, a reaction force of the clamping force is generated in the stationary platen 14. In the stationary platen 14 of the comparative example, a gap GP4 is formed between the load transmission block 200 and the tie bar support portion 146. Therefore, even if a reaction force of the clamping force is generated in the stationary platen 14, the variation in the load applied to the stationary mold 120 is reduced compared to when the gap GP4 is not formed.

[0043] However, a force (bending force) acts on the tie bar 20 of the comparative example, tending to bend the tie bar 20, and the load transmission block 200 of the fixed platen 14 and the connecting portion 182 of the movable platen 18 tend to be excessively distorted. Therefore, there is a risk that the tie bar 20 may be easily deformed.

[0044] 5 is a schematic diagram showing the state of the mold clamping unit 10 in this embodiment during mold clamping. In the stationary platen 14 of this embodiment, a main body 140 is provided with a protruding portion 142 and a fixed portion 144. The fixed portion 144 is supported by the protruding portion 142 so as to be displaceable relative to the main body 140. More specifically, the fixed portion 144 is separated from the main body 140. Furthermore, the fixed portion 144 is separated from the protruding portion 142 by a gap GP1.

[0045] Therefore, in this embodiment, when a reaction force of the mold clamping force is generated in the stationary platen 14, the protrusions 142 are deformed, thereby canceling out the bending force of the tie bars 20. This reduces distortion of the tie bars 20. As a result, deformation of the tie bars 20 can be suppressed.

[0046] In this embodiment, the protrusion 142 is inclined so that the amount of protrusion from the main body 140 increases toward the second surface 152. In other words, the distance DT1 between the protrusion end E1 of the protrusion 142 and the first surface 150 of the main body 140 in the opening / closing direction D1 of the mold 12 is greater than the distance DT2 between the base end E2 of the protrusion 142 and the first surface 150 of the main body 140 in the opening / closing direction D1 of the mold 12.

[0047] This makes it easier for the protruding portion 142 to deform compared to when the protruding portion 142 protrudes in the same direction as the protruding direction D22 of the tie bar support portion 146. As a result, distortion of the tie bar 20 can be effectively alleviated.

[0048] In this embodiment, the protruding portion 142 is located between the fixing portion 144 and the tie bar support portion 146, and the protruding portion 142 and the tie bar support portion 146 face each other across a space.

[0049] This reduces the variation in the load applied to the fixed mold 120 when a reaction force of the mold clamping force occurs on the fixed platen 14, compared to when no gap GP2 is formed between the protrusion 142 and the tie bar support portion 146.

[0050] Fig. 6 is an external view showing a mold clamping apparatus 10 in a modified example. Fig. 7 is a schematic diagram showing a state of the mold clamping apparatus 10 in a modified example during mold clamping. In Fig. 6 and Fig. 7, the same reference numerals are used for components equivalent to those described in the above embodiment. Note that in this modified example, descriptions that overlap with the above embodiment will be omitted.

[0051] In the mold clamping unit 10 of the modified example, the thickness of the protruding portion 142 in the opening / closing direction D1 of the mold 12 is greater than the thickness of the protruding portion 142 of the above embodiment. As a result, the fixed portion 144 is located further in the closing direction D10 than the second surface 152 of the fixed platen 14.

[0052] 7, when a reaction force of the mold clamping force is generated in the stationary platen 14, the protrusions 142 are deformed, thereby counteracting the bending force of the tie bars 20, as in the above embodiment. This reduces distortion of the tie bars 20. As a result, deformation of the tie bars 20 can be suppressed. Furthermore, in this modification, even when a relatively large reaction force of the mold clamping force is generated in the stationary platen 14, distortion of the tie bars 20 can be reduced.

[0053] The following additional notes are further disclosed regarding the above embodiment.

[0054] (Supplementary Note 1) The fixed platen (14) of the present disclosure is a fixed platen provided in a mold clamping device (10) that opens and closes a mold (12) along the direction in which tie bars (20) extend, and comprises: a main body (140) to which the mold is attached; a protruding portion (142) that protrudes from the main body in a first direction (D20) intersecting the mold opening / closing direction (D1) and has a first insertion hole (142H) through which the tie bar is inserted; and a fixed portion (144) that is connected to a protruding end (E1) of the protruding portion, has a second insertion hole (144H) through which the tie bar is inserted, and to which an end of the tie bar is fixed, and the fixed portion is supported by the protruding portion so as to be freely displaceable relative to the main body.

[0055] (Supplementary Note 2) In the fixed platen described in Supplementary Note 1, the portion of the protruding portion through which the tie bar is inserted and the portion of the fixed portion through which the tie bar is inserted may face each other across a space.

[0056] (Appendix 3) In the fixed platen described in Appendix 1 or 2, the mold may be attached to a first surface (150) of the main body, and a distance (DT1) in the opening / closing direction between the protruding end of the protrusion and the first surface may be greater than a distance (DT2) in the opening / closing direction between the base end (E2) of the protrusion and the first surface.

[0057] (Appendix 4) The fixed platen according to any one of Appendices 1 to 3 further comprises a tie bar support portion (146) that protrudes in a second direction (D22) intersecting the opening / closing direction, has a third insertion hole (146H) through which the tie bar is inserted, and supports the tie bar, the protruding portion being located between the tie bar support portion and the fixed portion, and the tie bar support portion and the protruding portion may face each other across a space.

[0058] (Appendix 5) The mold clamping device of the present disclosure includes a fixed platen described in any one of Appendices 1 to 4, a rear platen (16) arranged at a distance from the fixed platen, the tie bar having one end fixed to the fixed platen and the other end fixed to the rear platen, and a movable platen (18) arranged movably along the tie bar.

[0059] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0060] REFERENCE SIGNS LIST 10... Mold clamping device 12... Mold 14... Fixed platen 16... Rear platen 18... Movable platen 20... Tie bar 22... Mold clamping drive section 120... Fixed mold 122... Movable mold 140, 180... Main body section 142... Protrusion section 144... Fixed section 146, 184... Tie bar support section 182... Connection section

Claims

1. A fixed platen provided in a mold clamping device that opens and closes a mold along the direction in which the tie bar extends, the fixed platen comprising: a main body portion to which the mold is attached; a protruding portion protruding from the main body portion in a first direction intersecting the opening and closing direction of the mold, and having a first insertion hole through which the tie bar is inserted; a fixing portion connected to the protruding end of the protruding portion, having a second insertion hole through which the tie bar is inserted, and fixing the end of the tie bar; wherein the fixing portion is supported by the protruding portion so as to be displaceable with respect to the main body portion.

2. The fixed platen according to claim 1, wherein a portion of the protruding portion through which the tie bar is inserted and a portion of the fixing portion through which the tie bar is inserted face each other with a space therebetween.

3. The fixed platen according to claim 1 or 2, wherein the mold is attached to a first surface of the main body portion, and a distance in the opening and closing direction between the protruding end of the protruding portion and the first surface is greater than a distance in the opening and closing direction between the base end of the protruding portion and the first surface.

4. The fixed platen according to any one of claims 1 to 3, further comprising a tie bar support portion protruding in a second direction intersecting the opening and closing direction and having a third insertion hole through which the tie bar is inserted, for supporting the tie bar, wherein the protruding portion is located between the tie bar support portion and the fixing portion, and the tie bar support portion and the protruding portion face each other with a space therebetween.

5. A mold clamping device comprising: the fixed platen according to any one of claims 1 to 4; a rear platen arranged at a distance from the fixed platen; the tie bar having one end fixed to the fixed platen and the other end fixed to the rear platen; and a movable platen arranged to be movable along the tie bar.

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