JP4133974B2 - Vertical mold clamping mechanism - Google Patents

Description

  The present invention relates to a mold clamping mechanism essential for an injection molding machine.

The injection molding machine is mainly a horizontal injection molding machine, but a vertical injection molding machine is also put to practical use because it has an advantage such as a small installation area (see, for example, Patent Document 1).
JP 2002-172672 A (FIG. 1)

Patent document 1 is demonstrated based on the following figure.
FIG. 8 is a diagram for explaining the basic configuration of the prior art, in which a support 102 (... Indicates a plurality, the same applies below) is set up on the base member 101, and a stationary platen 103 is placed on these supports 102. , A plurality of tie bars 104... Are vertically passed through the fixed plate 103, the movable plate 105 is fixed to the upper ends of these tie bars 104, and the end plate 107 that supports the toggle link 106 at the lower end of the tie bars 104. And the end plate 107 is moved up and down by rotating the ball screw shaft 108.

  On the other hand, a plurality of guide rods 113 are set up on the movable platen 105, and a heating plate holding plate 115 that holds the heating tube 114 and a moving plate 117 that supports the driving device 116 are movable on these guide rods 113. Install.

  Then, the end plate 107 is lowered, the movable plate 105 is lowered together with the tie bars 104..., The upper die 112 is aligned with the lower die 111, and the die is clamped. Next, the screw 118 is advanced (lowered in the drawing) by the driving device 116 to perform injection.

  Structures higher than the movable platen 105 (guide rod 113..., Heating cylinder 114, heating cylinder holding plate 115, driving device 116, moving plate 117, etc.) are called injection devices, but the injection device is located above the movable platen 105. It is quite heavy as it grows greatly.

The weight of the injection device including the heating cylinder 114 is carefully positioned to act on the center of adjacent tie bars 104,104.
However, since the heating cylinder 114 has a built-in heater and thermally expands itself and thermally expands the surrounding support members, the one acting on the center of the adjacent tie bars 104 and 104 at the time of assembly at room temperature is When operating at a high temperature, the tie bars 104, 104 adjacent to each other will deviate from the center.

A load that deviates from the center is referred to as an uneven load. If an uneven load exists, a horizontal load acts on the tie bars 104... In addition to a downward load, causing a disadvantage that the tie bars 104. The same applies to the case where the load is offset due to the structure of the injection apparatus.
As a result, in the process of lowering the upper mold 112, the upper portions of the tie bars 104. Insufficient mold alignment will cause molding defects due to misalignment.

  An object of the present invention is to provide a vertical mold clamping mechanism capable of preventing a tie bar from swinging and preventing a molding defect from occurring in a vertical injection molding machine.

According to the first aspect of the present invention, there is provided a support plate (12) arranged horizontally and supporting a clamping cylinder (17) or a toggle, a plurality of tie bars (13) raised from the support plate (12) , and these A fixed platen (14) that is fixed to the upper portion of the tie bar (13) and supports the fixed die (24), and a movable platen that is attached to the middle of the tie bar (13) so as to be movable up and down and supports the movable die (25) ( 16), and a vertical mold clamping mechanism (10) used in a vertical injection molding machine in which an injection device is mounted on the stationary platen (14) .
The fixed platen (14) is supported by a mold clamping mechanism support member (11) erected on a base member (18) , and
A guide cylinder (15) having a large inner diameter that opens a gap with the outer peripheral surface of the tie bar (13) is extended from the fixed platen (14) so as to surround the tie bar (13), and these guides are extended. The cylinder (15) is passed through the movable platen (16) and the tip is free, and the guide plate (15) guides the movable platen (16) with reference to the fixed platen (14). It is characterized by that.

The invention according to claim 2 comprises a support plate (12) arranged horizontally and supporting the clamping cylinder (17) or toggle, a plurality of tie bars (13) standing from the support plate (12), and these A fixed platen (14) that is fixed to the upper portion of the tie bar (13) and supports the fixed die (24), and a movable platen that is attached to the tie bar (13) so as to be movable up and down and supports the movable die (25) ( 16), and a vertical mold clamping mechanism (10B) used in a vertical injection molding machine in which an injection device is mounted on the stationary platen (14).
The fixed platen (14) is supported by a mold clamping mechanism support member (11) erected on a base member (18), and
The movable platen (16) is provided with a large-diameter through hole (39) that opens a gap with the outer peripheral surface of the tie bar (13), and the tie bar (13) is passed through the through hole (39),
In addition to the tie bar (13), a plurality of guide rods (15B) are extended from such a movable plate (16), and these guide rods (15B) are passed through the fixed plate (14) and the tip becomes a free end. Thus, the guide plate (15B) guides the movable platen (16) with respect to the fixed platen (14) .

The invention according to claim 3 is characterized in that the mold clamping mechanism support member (11) is composed of four support columns that support the four corners of the fixed platen (14) .

In the invention according to claim 4, the roller bearing (30) is interposed between the guide tube (15) and the movable platen (16) or between the guide rod (15B) and the fixed platen (14). It is characterized by.

The invention according to claims 1 and 2 is characterized in that the fixed plate of the vertical mold clamping device is supported by a mold clamping mechanism support member standing on the base member.
If the uppermost fixing platen is supported by the mold clamping mechanism support member, the injection device above the mold clamping mechanism support member and the mold clamping mechanism below can be structurally separated. Even if an external force such as a horizontal force is generated in the upper injection device, this external force does not reach the lower mold clamping mechanism. If an inconvenient external force does not act on the mold clamping mechanism, a highly accurate molded product can be produced.

In addition, in the inventions according to claims 1 and 2, the tie bar that receives the clamping force and the guide cylinder or the guide rod that determines the position of the movable platen are provided separately. As a result, the tie bar is not involved in the guide of the movable platen. For this reason, the tie bar may be thinned, bent or deformed. On the other hand, the guide tube or the guide rod is not connected to the support plate by making the tip end free. Therefore, a tensile force does not act on the guide tube or the guide rod. Since the horizontal position of the movable platen is determined by such a guide tube or guide rod, the positioning accuracy at the time of mold matching can be dramatically improved.

In the invention according to claim 3, the mold clamping mechanism support member is constituted by four columns supporting the four corners of the fixed platen. The structure is simple, and the main part of the mold clamping mechanism can be observed and inspected freely between adjacent struts.

In the invention according to claim 4, the roller bearing is interposed between the guide cylinder and the movable platen or between the guide rod and the fixed platen. Since the roller bearing has a small frictional resistance, the positioning accuracy can be further increased.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a front view of a vertical mold clamping mechanism according to the present invention. The vertical mold clamping mechanism 10 includes a horizontal support plate 12 and a plurality of vertical plates (preferably four). Tie bars 13..., A fixed platen 14 hung over the tie bars 13... And a plurality of guide tubes 15 (preferably four) as guide members hanging from the fixed platen 14. A movable plate 16 that moves up and down along the guide cylinders 15..., A mold clamping cylinder 17 that is attached to the support plate 12 as means for moving the movable plate 16 up and down, and a die that supports the fixed platen 14. The fastening mechanism support member 11 has a basic configuration.

  The mold clamping mechanism support member 11 is fixed to the base member 18 or a corresponding strong structure. The mold clamping mechanism support member 11 includes a saddle mold clamping mechanism and an injection device, such as a bowl-shaped member composed of four support columns, a box-shaped member whose front and rear surfaces are opened, and a truss-shaped member combined with steel materials. Any structure and structure can be used as long as the structure supports the included injection molding machine.

By making the inner diameter of the guide cylinder 15 sufficiently larger than the outer diameter of the tie bar 13, the bending or inclination of the tie bar 13 is prevented from affecting the guide cylinder 15.
Next, the guide cylinder 15 suspended from the fixed platen 14 and penetrating through the movable platen 16 is a cantilever having a lower end as a free end.

  Then, the tie bar 13 is stored in the guide tube 15. That is, since the diver 13 is covered with the guide cylinder 15, the guide cylinder 15 hardly interferes and can be easily incorporated into a conventional mold clamping mechanism including a tie bar.

Reference numeral 21 denotes a ring, and reference numeral 22 denotes a nut. The ring 21 and the nut 22 fix the lower end of the tie bar 13 to the support board 12 and the upper part of the tie bar 13 to the fixing board 14.
Reference numeral 23 denotes a heating cylinder of the injection device, 24 denotes a fixed mold attached to the fixed platen 14, and 25 denotes a movable type attached to the movable platen 16.

  Reference numeral 26 denotes a hemisphere provided at the tip of the piston rod 29 of the mold clamping cylinder 17, 27 denotes a spherical seat for housing the hemisphere 26, and 28 denotes a retaining ring. The parallelism between the guide cylinder 15 and the piston rod 29 is incorrect. If there is, the guide cylinder 15 is made positive so that the movable platen 16 is inclined with respect to the piston rod 29.

  2 is a cross-sectional view taken along the line 2-2 in FIG. 1. A roller bearing structure 30 includes a bush 31 integrally attached to the movable platen 16 side, and an abacus ball roller 32 disposed in the bush 31. And needle bearings 33 ... and triangular grooves 34 ... and flat surfaces 35 ... provided in the guide cylinder 15 for contact with these rollers 32 ... and needle bearings 33 ... . Reference numeral 36 denotes a retainer which prevents the rollers 32... And the needle bearings 33.

  The triangular groove 34 and the flat surface 35 provided in the guide tube 15 can be precisely finished. Since the rollers 32... And the needle bearings 33... Which are precision parts are brought into contact therewith, the radial gap of the guide cylinder 15 can be strictly managed. As a result, precise mold matching can be realized.

  In addition to the above, the roller bearing structure 30 can also adopt a linear guide mechanism, and is not a sliding bearing, but a roller bearing including rollers such as rollers, needles, conical rollers, balls, etc. The structure of the rollers is arbitrary.

Next, the operation of the vertical mold clamping mechanism having the above configuration will be described.
FIG. 3 is an explanatory view of the overall operation of the vertical mold clamping mechanism of the present invention.
(A) shows the mold open state, and the movable platen 16 is raised by the push-up action of the mold clamping cylinder 17. At this time, since no particular horizontal external force acts on the movable platen 16, the movable platen 16 starts to rise while being guided by the guide cylinders 15.

  (B) shows a state immediately before mold clamping, and shows that the movable mold 25 is smoothly engaged with the positioning pins 38 and 38 extended from the fixed mold 24 by the accurate guide of the guide cylinder 15. . Further, the movable platen 16 is raised by the mold clamping cylinder 17.

  (C) shows the mold clamping state, and the tie bars 13... Are pulled and extended by the pressing force of the mold clamping cylinder 17. However, since the horizontal position of the movable platen 16 is regulated by the guide cylinders 15..., There is no fear that the influence of the extension of the tie bars 13.

  By the way, if the lower end of the guide tube 15 is extended and fixed to the support board 12, the mold clamping force also affects the guide tube 15. In order to eliminate this influence, the guide tube 15 is a cantilever beam fixed only to the fixed platen 14, and the lower end is a free end. If the lower end is a free end, no matter how much the tie bar 13 extends, the guide tube 15 only moves upward as a whole, and no tensile force acts on the guide tube 15.

Next, it is examined whether or not the present invention can be applied to a horizontal mold clamping mechanism in which the tie bar 13 is placed horizontally.
Since the guide tube 15 is a cantilever beam, it bends downward when a load is applied downward. When the guide tube 15 is bent, the position accuracy of the movable platen 14 cannot be obtained. On the other hand, in the case of the saddle type described in the embodiment, a downward load does not act on the guide cylinder 15. For this purpose, the present invention is applied to a vertical mold clamping mechanism.

FIG. 4 is a diagram for studying deformation of the tie bar. The tie bars 13 may be misaligned due to mounting errors, bend under the influence of heat such as a heating cylinder (see reference numeral 23 in FIG. 1), or may be elongated and narrowed during mold clamping.
(A) shows that the center of the tie bar 13 is shifted from the center of the guide tube 15 by δ. However, since the inner diameter of the guide cylinder 15 is sufficiently large, there is no concern that the tie bar 13 contacts the guide cylinder 15.

(B) indicates that the tie bar 13 is bent. However, since the inner diameter of the guide cylinder 15 is sufficiently large, there is no concern that the tie bar 13 contacts the guide cylinder 15.
In (c), it is assumed that the tie bar 13 is thinned as indicated by an imaginary line. The narrowing of the tie bar 13 does not affect the guide tube 15 at all.

Thus, in the present invention, since the horizontal position of the movable platen 16 is regulated by the guide cylinder 15, the position accuracy of the movable platen 16 can be greatly improved.
In addition, since the tie bar 13 does not participate in the positioning of the movable platen 16 and only serves as a tension member, the outer diameter can be freely selected and the diameter can be reduced.

Returning to FIG. 1, this embodiment is characterized in that the stationary platen 14 is supported by the mold clamping mechanism support member 11.
Since the fixed platen 14 is supported by the mold clamping mechanism support member 11, the fixed platen 14 is fixed. Guide cylinders 15, 15, movable plate 16, tie bar 13, support plate 12, and mold clamping cylinder 17 are suspended from such a fixed platen 14. Since the clamping cylinder 17 and the support board 12 are heavy objects, they serve as weights and serve to make the tie bar 13 vertical.

  On the other hand, since the heating cylinder 23 above the fixed platen 14 has a built-in heater, when the heater is energized, it is thermally expanded as a whole, and the influence acts on the upper portion of the tie bar 13 as a horizontal force. Then, the upper part of the tie bar 13 is curved. The influence of this bending is blocked by the fixed platen 14 and hardly affects the mold clamping mechanism 10 side. Therefore, the mold clamping mechanism 10 can perform precise molding.

In order to clarify the operational effects of the present embodiment described above, the embodiment will be described in comparison with a comparative example.
FIG. 5 is a comparison diagram between the example and the comparative example.
(A) shows an embodiment, and it is assumed that the center of gravity G1 of the injection apparatus including the heating cylinder 23 is located at a distance L1 from the center of the height of the fixed platen 14. It is assumed that the angle θ1 has swung at the point of the center of gravity G1 due to the eccentric load.

  Since this deflection does not propagate downward from the fixed platen 14, it hardly affects the clamping by the fixed mold 24 and the movable mold 25.

  Even if the tie bars 13 and 13 are bent due to the influence, the deformation of the tie bar 13 does not affect the guide cylinders 15 and 15 as described in FIGS. Since the movable platen 16 is raised by being guided by such guide cylinders 15, 15, the movable mold 25 can be accurately matched to the fixed mold 24.

  (B) shows a comparative example, and it is assumed that the center of gravity G2 of the injection apparatus including the heating cylinder 114 is located at a distance L1 from the height center of the movable platen 105. However, since the member supported by the columns 102 and 102 is the fixed platen 103, the center of swing of the center of gravity G2 is the height center of the fixed platen 103. The distance L2 from the fixed platen 103 to the center of gravity G2 is larger than the distance L1. Therefore, if there is an offset load, the center of gravity G2 will swing greatly. That is, even if the deflection angle θ2 is the same as θ1 in (a), the amount of deflection is proportional to the distance, and therefore increases at a ratio of L2 / L1.

This adversely affects the injection device itself including the heating cylinder 114, and it is necessary to take measures such as increasing the diameter of the tie bars 104 and 104.
However, even if the tie bars 104, 104 are made large in diameter and the bending rigidity is increased, the tie bars 104, 104 continue through the stationary platen 103, so that the influence of the deflection angle θ2 is affected by the upper die 112 and the end plate 107. It extends to.

If the tie bars 104, 104 are curved, the upper mold 112 is inclined with respect to the lower mold 111, making it difficult to align the molds, resulting in molding defects.
Further, if the tie bars 104, 104 are bent, the end plate 107 is tilted, adversely affecting the toggle link 106, making uniform mold clamping difficult and causing molding defects.
Therefore, in a vertical injection molding machine, it can be said that (a) is remarkably superior to (b).

Next, another embodiment of the present invention will be described.
FIG. 6 is a diagram showing another embodiment of FIG. 1, and components common to those in FIG.
The vertical mold clamping mechanism 10B raises guide rods 15B and 15B as guide members from the movable platen 16. These guide rods 15B and 15B pass through the fixed platen 14 so that the upper end is a free end. The movable plate 16 is guided by the guide rods 15B and 15B with the fixed plate 14 as a reference.

The guide rods 15B and 15B are provided separately from the tie bars 13 and 13. Then, a large-diameter through hole 39 is opened in the movable platen 16 and the tie bar 13 is passed through the through hole 39.
When the inner diameter of the through hole 39 is D and the outer diameter of the tie bar 13 is d, the relationship d <D is established. As a result, the tie bar 13 does not have a function of guiding the movable platen 16. The movable platen 16 is guided by guide rods 15B and 15B.

  FIG. 7 is a cross-sectional view taken along the line 7 in FIG. 6. The bearings 33 are composed of triangular grooves 34 provided on the guide rod 15B for contact with the rollers 32 and needle bearings 33, and flat surfaces 35. Reference numeral 36 denotes a retainer which prevents the rollers 32... And the needle bearings 33.

  The triangular groove 34 and the flat surface 35 provided on the guide rod 15B can be precisely finished. Since the rollers 32... And the needle bearings 33... That are precision parts are brought into contact therewith, the radial gap of the guide rod 15B can be strictly managed. As a result, precise mold matching can be realized.

  As illustrated in FIG. 1 and FIG. 6, in the present invention, a plurality of guide members (guide cylinder 15 or guide rod 15 </ b> B) are extended from the fixed platen 14 or the movable platen 16 separately from the tie bar 13, 15B is made to penetrate the movable platen 16 or the fixed platen 14 and the tip is a free end, and the movable platen 16 is guided by the guide member 15 or 15B with reference to the fixed platen 14. .

In the first to third aspects, the bush may be directly brought into sliding contact with the rod without interposing a roller bearing between the movable platen or the fixed platen and the guide member.
Further, the mold clamping cylinder described in the embodiment can be changed to a toggle link.

The present invention is applied to a vertical injection molding machine.

It is a front view of a vertical mold clamping mechanism concerning the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a whole operation explanatory view of the vertical mold clamping mechanism of the present invention. It is a figure which examines a deformation | transformation of a tie bar. It is a comparison figure of an Example and a comparative example. It is another Example figure of FIG. FIG. 7 is a sectional view taken along line 7 in FIG. 6. It is a figure explaining the basic composition of the conventional technology.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10B ... Vertical mold clamping mechanism, 11 ... Clamping mechanism support member, 12 ... Supporting board, 13 ... Tie bar, 14 ... Fixing board, 15 ... Guide cylinder as guide member, 15B ... Guide rod as guide member, DESCRIPTION OF SYMBOLS 16 ... Movable board, 17 ... Clamping cylinder, 18 ... Base member, 24 ... Fixed type | mold, 25 ... Movable type | mold, 30, 30B ... Roller bearing.

Claims (4)

A support plate (12) arranged horizontally and supporting the clamping cylinder (17) or toggle, a plurality of tie bars (13) raised from the support plate (12 ), and an upper portion of these tie bars (13) The fixed plate (14) for fixing and supporting the fixed die (24), and the movable plate (16) for mounting in the middle of the tie bar (13) so as to be movable up and down and supporting the movable die (25), are fixed. In a vertical mold clamping mechanism (10) used in a vertical injection molding machine in which an injection device is mounted on a panel (14) ,
The fixed platen (14) is supported by a mold clamping mechanism support member (11) erected on a base member (18) , and
A guide cylinder (15) having a large inner diameter that opens a gap with the outer peripheral surface of the tie bar (13) is extended from the fixed platen (14) so as to surround the tie bar (13), and these guides are extended. The cylinder (15) is passed through the movable platen (16) and the tip is free, and the guide plate (15) guides the movable platen (16) with reference to the fixed platen (14). A vertical mold clamping mechanism characterized by that. A support plate (12) arranged horizontally and supporting the clamping cylinder (17) or toggle, a plurality of tie bars (13) raised from the support plate (12), and an upper portion of these tie bars (13) The fixed plate (14) for fixing and supporting the fixed die (24), and the movable plate (16) for mounting in the middle of the tie bar (13) so as to be movable up and down and supporting the movable die (25), are fixed. In the vertical mold clamping mechanism (10B) used in the vertical injection molding machine in which the injection device is mounted on the panel (14),
The fixed platen (14) is supported by a mold clamping mechanism support member (11) erected on a base member (18), and
The movable platen (16) is provided with a large-diameter through hole (39) that opens a gap with the outer peripheral surface of the tie bar (13), and the tie bar (13) is passed through the through hole (39),
In addition to the tie bar (13), a plurality of guide rods (15B) are extended from such a movable plate (16), and these guide rods (15B) are passed through the fixed plate (14) and the tip becomes a free end. Thus, the vertical mold clamping mechanism is characterized in that the movable platen (16) is guided by the guide rods (15B) with respect to the fixed platen (14) . The vertical mold clamping mechanism according to claim 1 or 2, wherein the mold clamping mechanism support member (11) is constituted by four columns supporting four corners of the fixed platen (14) . A roller bearing (30) is interposed between the guide tube (15) and the movable platen (16) or between the guide rod (15B) and the fixed platen (14). The vertical mold clamping mechanism according to claim 1 or 2 .

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