JP2004330780A - Clamping mechanism in molding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a ball spline shaft small in a structure for preventing inclination of a moving platen using a ball spline cylinder and to make production easy by cost down. <P>SOLUTION: The clamping mechanism comprises a fixed platen 2 placed on a desk of a machine, a rear platen 3, a tie-bar 5 connecting the fixed platen and the rear platen and a moving platen 4 placed between the rear platen and the fixed platen, in which clamping of dies installed in the moving platen 4 and the fixed platen 2 is conducted by transporting the moving platen 4 along the tie-bar 5. At least 2 moving platen guides 13 other than the tie-bar 5 are provided, and at least the part sliding with the moving platen 4 in the moving platen guides 13 is used as the ball spline cylinder 14, and the moving platen 4 is inserted into the moving platen guides 13 and ball spline nuts 6a and 6b are provided in a hole inserted in the moving platen guides 13 in the moving platen 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mold clamping mechanism in a molding machine such as an injection molding machine.

  FIG. 11 is a schematic diagram for explaining an example of a mold clamping mechanism of a conventional molding machine such as an injection molding machine. In a mold clamping mechanism of a molding machine such as an injection molding machine, a fixed platen 2 is erected and attached to a base frame 1 of the molding machine, and the fixed platen 2 and the rear platen 3 are usually connected by four tie bars 5. A movable platen 4 having a through hole through which the tie bar 5 passes is disposed between the fixed platen 2 and the rear platen 3. The movable mold 17a is attached to the movable platen 4, the fixed mold 17b is attached to the fixed platen 2, and the movable platen 4 is driven by a driving source such as a motor or a hydraulic cylinder, and the tie bar 5 is used as a guide. The moving platen 4 is moved to clamp the dies 17a and 17b.

  A sliding bearing 15 is used on a sliding surface between the movable platen 4 and the tie bar 5. Bushes 15a and 15b of the slide bearing are arranged in through holes provided in the movable platen, and the tie bar 5 penetrates the bushes 15a and 15b.

  In the conventional mold clamping mechanism as described above, since the sliding bearing is used for the sliding portion between the moving platen and the tie bar, the clearance and play between the bush inner diameter and the tie bar outer diameter of the sliding bearing are increased. Therefore, the moving platen is easily tilted. As a result, the parallelism between the surface of the movable mold attached to the moving platen and the surface of the fixed mold attached to the fixed platen decreases.

  In order to prevent the movable platen from tilting, a mold clamping mechanism of a molding machine in which a ball spline nut is provided in a tie bar insertion hole of the movable platen and at least a sliding portion of the tie bar with the movable platen is a ball spline shaft, 1 is proposed.

Patent No. 3330578

  FIG. 12 is a schematic diagram of a conventional mold clamping mechanism disclosed in Patent Document 1, and FIG. 13 is a diagram viewed from A in FIG. The moving platen 4 is moved along the tie bar 5 by a ball spline mechanism constituted by ball spline nuts 6 a and 6 b provided in the insertion hole and a ball spline shaft 14 provided in the tie bar 5.

  Since the conventional ball spline shaft also receives a mold clamping force, its shaft diameter needs to be equal to or larger than the tie bar shaft. Therefore, when this configuration is applied to a large-sized machine, there is a problem that the ball spline shaft becomes unnecessarily large in diameter and the cost is increased, and there is a problem that manufacturing is difficult.

  In view of the above, the present invention has been made to solve the above-mentioned conventional problems, and has an object to reduce the shaft diameter of the ball spline shaft in a configuration in which the ball spline shaft is applied to prevent the inclination of the moving platen. It is intended to reduce the size and facilitate the production.

  The mold clamping mechanism of the molding machine of the present invention is provided with a moving platen guide for guiding the moving platen separately from the tie bar, and by providing a ball spline on the moving platen guide, the moving platen is prevented from being inclined. Since this moving platen guide does not bear the mold clamping force, no large force is applied. For this reason, a large diameter that can withstand the mold clamping force is not required, and an appropriate diameter for the guide is sufficient, so that the production cost can be reduced and the production can be facilitated. This is particularly effective when applied to a mold clamping mechanism of a large molding machine.

The aspect of the mold clamping mechanism of the molding machine of the present invention includes a fixed platen provided on the machine base, a rear platen, a tie bar connecting the fixed platen and the rear platen, and a moving platen located between the rear platen and the fixed platen. A mold clamping mechanism of a molding machine for clamping a mold attached to the movable platen and the fixed platen by moving the movable platen along the tie bar, wherein at least two movable platen guides separate from the tie bar are provided. In this configuration, at least a sliding portion of the moving platen guide with the moving platen is a ball spline shaft, the moving platen is inserted into the moving platen guide, and a ball spline nut is provided in the moving platen guide insertion hole of the moving platen. is there.
The mold is fixed to a movable platen and a fixed platen, and the movable platen is moved along a tie bar to open / close, close, and open the mold.

  Both ends of the tie bar are fixed to the fixed platen and the rear platen. On the other hand, one end of the movable platen guide is fixed by a fixed platen, and the other end is simply supported on the rear platen side. As a result, the mold clamping force is imposed on the tie bar, the moving platen guide is not imposed with the mold clamping force, and the moving platen guide only guides the moving platen. In this configuration, a ball spline nut is provided in the insertion hole of the moving platen guide, and at least a sliding portion of the moving platen guide with the moving platen is used as a ball spline shaft.

  Since no clamping force is applied to the moving platen guide, it is not necessary to increase the diameter of the ball spline shaft, and the diameter suitable for the guide can be reduced. Thereby, a ball spline can be applied as a configuration for preventing the inclination of the moving platen.

  The moving platen of the present invention can be composed of two members, a moving member and an auxiliary member fixed to the fixed platen side of the moving member, and is fixed by bolts or the like. The auxiliary member reduces the influence of the distortion of the moving platen due to the mold clamping force on the ball spline.

  Further, different materials for the moving platen and the auxiliary member may be used. For example, a material having higher rigidity than the moving platen is used for the auxiliary member. Here, high rigidity means a material having a large longitudinal elastic modulus. For example, when gray cast iron or spheroidal graphite cast iron is used for the moving platen, rolled steel for general structure, carbon steel for general structure, or alloy steel for general structure having a modulus of longitudinal elasticity approximately twice as large as these is used for the auxiliary platen.

  Generally, the structure of the moving platen is complicated, and the structure of the auxiliary member can be simplified. A material having a large modulus of longitudinal elasticity is difficult to process and causes a cost increase. In the present invention, the material of the moving platen having a complicated structure is made of a material having a small longitudinal elastic modulus, and the material of the auxiliary member having a simple structure is made of a material having a large longitudinal elastic modulus, thereby facilitating processing and reducing costs. be able to.

  Further, the mold clamping mechanism of the molding machine of the present invention includes a guide support between the rear platen and the moving platen. The guide support is a member that supports the moving platen guide by inserting it, and can support the moving platen guide instead of the rear platen. This guide support is connected to the rear platen by a connecting member.

  As described above, according to the present invention, in the configuration in which the ball spline shaft is applied to prevent the tilting of the moving platen, the diameter of the ball spline shaft can be reduced, and the cost can be reduced. Can be facilitated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The first embodiment of the present invention will be described with reference to FIGS. 1 to 4, the second embodiment will be described with reference to FIGS. 5 to 7, and the third embodiment will be described with reference to FIGS. 8 and 9. .
First, a first mode in which a moving platen is guided by a moving platen guide provided with a ball spline shaft will be described.

FIG. 1 is a schematic view of a mold clamping mechanism according to an embodiment of the first aspect of the present invention, showing an embodiment in which a moving platen guide is provided and a ball spline shaft is provided in the moving platen guide.
In FIG. 1, a fixed platen 2 is mounted upright on a base frame 1 of a molding machine. Four tie bars 5 are fixed to the fixed platen 2, and a rear platen 3 is attached to the other end of the tie bar 5. The opposing surfaces of the fixed platen 2 and the rear platen 3 have a rectangular shape, and tie bars 5 are attached to the four corners thereof (FIG. 1 shows only one tie bar).

  The tie bar 5 is fixed to the fixed platen 2 with a nut or the like, and the rear platen 3 is mounted so as to be movable along the tie bar 5 via a nut 8 for adjusting the mold thickness. Reference numeral 9 denotes a pinion fixed to the nut. A chain (not shown) is provided between the pinions 9 provided for the respective tie bars 5, and is driven by a mold thickness adjusting motor or the like (not shown). At the same time, the rear platen 3 is moved by rotating the nut 8 of each tie bar 5 synchronously. Thereby, the distance between the rear platen 3 and the fixed platen 2 is adjusted, and the thickness of the mold to be used and the mold clamping force are adjusted.

  Further, a moving platen 4 is inserted into the four tie bars 5, and the moving platen 4 is disposed between the fixed platen 2 and the rear platen 3. A toggle mechanism 11 is disposed between the rear platen 3 and the movable platen 4, and a drive source 10 such as a servomotor for driving a crosshead 11 a of the toggle mechanism 11 is provided on the rear platen 3.

  Sliding bearing bushes 15a and 15b are provided in holes provided in the movable platen 4 through which the tie bar 5 is inserted. Further, instead of the slide bearing, the inner diameter of the tie bar insertion hole of the movable platen 4 is set to be larger than the outer diameter of the tie bar 5, so that the inner peripheral surface of the tie bar insertion hole of the movable platen 4 and the outer peripheral surface of the tie bar 5 are provided. A gap may be provided.

  At least two moving platen guides 13 are fixed to the fixed platen 2 of the first embodiment of the present invention by nuts and the like in addition to the tie bars described above. The other end of the movable platen guide 13 is inserted into a fitting hole of the rear platen 3, and the axis of the movable platen guide 13 is held at a position within a predetermined accuracy. The other end of the movable platen guide may be supported by a rear platen 3 or a guide support provided between the rear platen 3 and the movable platen 4. The mode of the support structure by the guide support will be described in a third mode.

  The moving platen guide 13 is provided with a ball spline at least in a range where the moving platen 4 slides, and is used as a ball spline shaft 14.

  The moving platen 4 includes ball spline nuts 6 a and 6 b at a portion where the moving platen guide 13 passes, and forms a ball spline mechanism together with the ball spline shaft 14 of the moving platen guide 13. In the example shown in FIG. 1, two ball spline nuts 6a and 6b are provided, but the number of ball spline nuts is arbitrary. By increasing the number of ball spline nuts, it is possible to increase the length of the ball spline engagement portion, and thereby it is possible to enhance the effect of preventing the tilt variation of the movable platen 4.

Next, the arrangement of the tie bar and the movable platen guide will be described with reference to FIGS. 2 to 4 which illustrate the arrangement of the tie bar and the movable platen guide.
2A and 2B show a first arrangement example. FIG. 2A is a top view of the moving platen 4, and FIG. 2B is a diagram of the moving platen 4 viewed from the direction of arrow A in FIG.

The moving platen 4 has two types of holes, a hole through which the tie bar 5 is inserted and a hole through which the moving platen guide 13 is inserted. The hole through which the tie bar 5 is inserted is provided with slide bearing bushes 15a and 15b to allow the tie bar 5 to be inserted. On the other hand, the hole through which the moving platen guide 13 is inserted has ball spline nuts 6a and 6b, and engages with the ball spline shaft 14 of the moving platen guide 13 to constitute a ball spline mechanism.
With this configuration, the movable platen 4 is inserted into the tie bar 5 by the slide bearing bushes 15a and 15b, and is engaged with the movable platen guide 13 via the ball spline nuts 6a and 6b.

Although the first arrangement example in FIG. 2 shows an example in which the movable platen guide 13 is arranged outside the tie bar 5, the arrangement relationship between the movable platen guide 13 and the tie bar 5 is not limited to this arrangement.
The second arrangement example shown in FIG. 3 shows an example in which the movable platen guide 13 is arranged inside the tie bar 5, and the third arrangement example shown in FIG. An example of disposing it below is shown. FIG. 4A shows an example in which the moving platen guide 13 is arranged inside the tie bar 5 in the vertical direction, and FIG. 4B shows an example in which the moving platen guide 13 is arranged above the tie bar 5. FIG. 4C shows an example in which the moving platen guide 13 is arranged below the tie bar 5. 2 (b), 3 (b) and 4, the arrangement by two moving platen guides 13 indicated by solid lines, the arrangement by two moving platen guides 13 indicated by dashed lines, or the solid line and Arbitrary numbers and combinations of arrangement positions, such as arrangement by four moving platen guides 13 indicated by dashed lines, can be used.

Reference numeral 16a in FIG. 1 denotes a platen support, which acts between the movable platen 4 and the base frame 1 to adjust the inclination of the platen.
A mold is attached to the opposing surfaces of the fixed platen 2 and the movable platen 4. Then, the drive source 10 is driven to drive the toggle mechanism 11, and the movable platen 4 is moved along the tie bar 5 to open / close, close, and open the mold.
That is, while the conventional mold clamping mechanism has a configuration in which a ball spline shaft is provided on a tie bar, the first embodiment has a configuration in which a moving platen guide separate from the tie bar is provided, and a ball spline shaft is provided in the moving platen guide. Are different.

Next, the second embodiment will be described. The second mode is a configuration including an auxiliary member that is coupled to the moving platen.
FIG. 5 is a schematic view of a mold clamping mechanism according to an embodiment of the second aspect of the present invention. The mold clamping mechanism includes an auxiliary member coupled to a moving platen, and the auxiliary member and the moving platen guide constitute a ball spline mechanism. It shows a form.
The second embodiment shown in FIG. 5 differs from the first embodiment in the point that the auxiliary member is provided. In the following, a configuration different from the first embodiment will be described, and a description of a common configuration will be omitted.

  The moving platen 4 and the auxiliary member 12 are inserted into the tie bar 5, and the moving platen 4 and the auxiliary member 12 are disposed between the fixed platen 2 and the rear platen 3. The auxiliary member 12 is engaged with the movable platen 4 by a fixing member such as a bolt. The auxiliary member 12 is inserted into the movable platen guide 13.

  Further, for each movable platen guide 13, a ball spline is provided at least in a range in which the auxiliary member 12 slides to form a ball spline shaft 14, and a hole provided in the auxiliary member 12 through which the movable platen guide 13 is inserted includes: Ball spline nuts 6a and 6b are provided. On the other hand, sliding bearing bushes 15a and 15b are provided in holes provided in the movable platen 4 through which the tie bar 5 is inserted. Further, instead of the slide bearing, the inner diameter of the tie bar insertion hole of the movable platen 4 is set to be larger than the outer diameter of the tie bar 5, so that the inner peripheral surface of the tie bar insertion hole of the movable platen 4 and the outer peripheral surface of the tie bar 5 are provided. A gap may be provided.

  That is, while the conventional mold clamping mechanism has a configuration in which a ball spline nut is provided in a hole provided in the moving platen and a tie bar is inserted, the second aspect of the present invention provides an auxiliary member, The configuration is different in that a ball spline nut is provided in a hole provided in the auxiliary member and the movable platen guide is inserted therethrough.

  The moving platen and the auxiliary member engaged with each other may use different materials. A material having higher rigidity than the moving platen is used for the auxiliary member. High rigidity means a material having a large longitudinal modulus of elasticity. For example, when gray cast iron or spheroidal graphite cast iron is used for the moving platen, a general structural rolled steel, a general structural carbon steel, or a general structural alloy steel having a modulus of longitudinal elasticity approximately twice as large as these is used for the auxiliary member.

  The moving platen has a complicated structure due to the provision of a toggle mechanism or the like, and it is common to use a material with low rigidity that is easy to cast. If the moving platen is formed of a material having high rigidity, the cost increases. On the other hand, since the auxiliary member may have a simple structure, complicated processing is not required. In the second aspect, by forming the auxiliary member using a material having high rigidity, the processing can be facilitated and the cost can be reduced.

Further, a mold is attached to the opposing surfaces of the fixed platen 2 and the movable platen 4. Then, the drive source 10 is driven to drive the toggle mechanism 11, and the movable platen 4 and the auxiliary member 12 are moved along the tie bar 5 to open / close, close, and open the mold. The movable platen 4, the auxiliary member 12, and the fixed platen 2 are deformed by the mold clamping force, but the movable platen 4 is directly connected to the toggle mechanism 11. Since the movable platen 4 is interposed between the movable platen 4 and the toggle mechanism 11, distortion is reduced. Thereby, deformation to the ball spline nut provided on the auxiliary member 12 can be reduced.
Next, the arrangement of the tie bar and the moving platen guide will be described with reference to FIGS. 6 and 7 which illustrate the arrangement of the tie bar and the moving platen guide.
6A and 6B show a first arrangement example. FIG. 6A is a top view of the movable platen 4 and the auxiliary member 12, and FIG. 6B is a view of the auxiliary member 12 viewed from the direction of arrow A in FIG. FIG.

  The moving platen 4 has a hole through which the tie bar 5 passes, and the auxiliary member 12 has two types of holes, through which the moving platen guide 13 passes. The hole through which the tie bar 5 is inserted is provided with slide bearing bushes 15a and 15b to allow the tie bar 5 to be inserted. On the other hand, the hole through which the moving platen guide 13 is inserted has ball spline nuts 6a and 6b, and engages with the ball spline shaft 14 of the moving platen guide 13 to constitute a ball spline mechanism.

  With this configuration, the tie bar 5 is inserted into the movable platen 4 by the slide bearing bushes 15a and 15b, while the auxiliary member 12 is engaged with the movable platen guide 13 via the ball spline nuts 6a and 6b.

  Although the first arrangement example in FIG. 6 illustrates an example in which the movable platen guide 13 is arranged outside the tie bar 5, the arrangement relationship between the movable platen guide 13 and the tie bar 5 is not limited to this arrangement. Further, the second arrangement example shown in FIG. 7 shows an example in which the moving platen guide 13 is arranged inside the tie bar 5.

  6 and 7, the arrangement by two moving platen guides 13 indicated by solid lines, the arrangement by two moving platen guides 13 indicated by dashed lines, or the four movements indicated by solid lines and dashed lines. Arbitrary numbers and combinations of arrangement positions, such as arrangement by the platen guide 13, can be used.

Next, a third mode will be described. A third mode is a configuration including a guide support that supports a moving platen guide.
FIG. 8 is a schematic view of a mold clamping mechanism according to an embodiment of the third aspect of the present invention, in which a guide support 18 is provided between the movable platen 4 and the rear platen 3, and the movable platen guide 13 is provided by the guide support 18. 1 shows an embodiment which constitutes a mechanism for supporting the above.

  The third embodiment shown in FIG. 8 is different from the first embodiment in that a guide support is provided. In the following, a configuration different from the first embodiment will be described, and a description of a common configuration will be omitted.

  The guide support 18 is supported by the tie bar 5 at two places between the movable platen 4 and the rear platen 3 via a slide bearing bush 15c. The rear platen 3 is connected to the rear platen 3 by connecting members 19a and 19b. The connecting members 19a and 19b may be integrated, may be separate components from the rear platen 3, or may be integrated with the rear platen 3. The guide support 18 supports the other end of the movable platen guide 13 by passing it through the opening. The guide support 18 may be provided with a support 16c for adjusting the height.

  9A and 9B show an arrangement example of the moving platen guide and the tie bar. FIG. 9A is a top view of the guide support 18, and FIG. 9B is a view of the guide support 18 viewed from the direction of arrow A in FIG. FIG.

  That is, there are a pair of guide supports 18 on the left and right sides, each of which has two slide bearing bushes 15c through which the tie bar 5 is inserted, and a hole through which the movable platen guide 13 is inserted at least at one position. I have. Thus, by providing the guide support 18 supporting one end of the movable platen guide 13 separately from the rear platen, the one end of the movable platen guide 13 can be adjusted up and down without exerting the action of the support 16c on the rear platen. Can be.

Next, a fourth embodiment will be described. The fourth mode is another configuration including a guide support for supporting the moving platen guide.
FIG. 10 is a schematic view of a mold clamping mechanism according to an embodiment of the fourth aspect of the present invention, in which a guide support 18 is provided between the movable platen 4 and the rear platen 3, and the movable platen guide 13 is provided by the guide support 18. 1 shows an embodiment which constitutes a mechanism for supporting the above.

  The fourth embodiment shown in FIG. 10 differs from the above-described second embodiment in the point that a guide support is provided. Hereinafter, a configuration different from the second embodiment will be described, and description of a common configuration will be omitted.

  The guide support 18 is supported by the tie bar 5 at two places between the movable platen 4 and the rear platen 3 via a slide bearing bush 15c. The rear platen 3 is connected to the rear platen 3 by connecting members 19a and 19b. The connecting members 19a and 19b may be integrated, may be separate components from the rear platen 3, or may be integrated with the rear platen 3. The guide support 18 supports the other end of the movable platen guide 13 by passing it through the opening. The guide support 18 may be provided with a support 16c for adjusting the height.

In each of the above aspects, the movable platen guide may be fixed to the rear platen or the guide support side with a nut or the like, and the fixed platen side may be supported as the other end.
Although the guide supports 18 of the third and fourth aspects are supported at two places by the tie bar 5 via the slide bearing bush 15c, and are connected to the rear platen 3 via the connecting members 19a and 19b, Regardless of the supporting method and the connecting method, it may be mounted upright on the base frame 1.

FIG. 1 is a schematic diagram of a mold clamping mechanism according to an embodiment of the first aspect of the present invention. FIG. 4 is a diagram for describing a first arrangement example of a tie bar and a moving platen guide according to the first embodiment of the present invention. FIG. 6 is a diagram for explaining a second arrangement example of the tie bar and the moving platen guide according to the first embodiment of the present invention. FIG. 9 is a diagram for explaining a third arrangement example of the tie bar and the moving platen guide according to the first embodiment of the present invention. It is a schematic diagram of a mold clamping mechanism of one embodiment of the second aspect of the present invention. It is a figure for explaining the 1st example of arrangement of a tie bar and a moving platen guide of a 2nd mode of the present invention. It is a figure for explaining the 2nd example of arrangement of a tie bar and a moving platen guide of a 2nd mode of the present invention. It is a schematic diagram of a mold clamping mechanism of one embodiment of the third mode of the present invention. It is a figure for explaining the example of arrangement of a tie bar and a moving platen guide of a 3rd mode of the present invention. It is a schematic diagram of a mold clamping mechanism of one embodiment of the fourth aspect of the present invention. It is a schematic diagram for explaining an example of a mold clamping mechanism of a conventional molding machine such as an injection molding machine. It is the schematic for demonstrating another example in the conventional mold clamping mechanism. It is the figure seen from A in FIG.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Base frame 2 Fixed platen 3 Rear platen 4 Moving platen 5 Tie bar 6a, 6b Ball spline nut 8 Nut for mold thickness adjustment 9 Pinion 10 Drive source 11 Toggle mechanism 12 Auxiliary member 13 Moving platen guide 14 Ball spline shaft 15a, 15b, 15c Slide bearing bush 16a, 16b Platen support 17a, 17b Mold 18 Guide support 19a, 19b Connecting member

Claims (3)

A fixed platen provided on a machine base, a rear platen, a tie bar connecting the fixed platen and the rear platen, and a moving platen located between the rear platen and the fixed platen; and moving the movable platen along the tie bar. In the mold clamping mechanism of the molding machine that performs mold clamping of the mold attached to the moving platen and the fixed platen by moving
Provide at least two moving platen guides separate from the tie bar,
At least a sliding portion of the moving platen guide with the moving platen is a ball spline shaft, the moving platen is inserted through the moving platen guide, and a ball spline nut is provided in a moving platen guide insertion hole of the moving platen. A mold clamping mechanism for a molding machine.   The mold clamping mechanism for a molding machine according to claim 1, wherein the moving platen includes a moving member and an auxiliary member fixed to a fixed platen side of the moving member. The mold clamping mechanism for a molding machine according to claim 1, further comprising a guide support between the rear platen and the moving platen, wherein the guide support penetrates and supports the moving platen guide. 4.

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