JP2004255598A - Mold clamping device of blow molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the forward tilting of a mold and to move the mold so that the mating surface of the mold is positioned at the predetermined center. <P>SOLUTION: The mold clamping device of blow molding machine is provided with the moving stand base 43 integrated with a moving stand 30. At least the under surfaces of one of first mold members (2, 17 and 21) and second mold members (3 and 10) are supported on the moving stand base 43 through support members 44 so as to freely move forward and rearward and the upward protruding deformation of rod 19a and 19b is suppressed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mold clamping device for a hollow molding machine, and more particularly to a mold clamping device for a hollow molding machine that suppresses tilting of a mold.
[0002]
[Prior art and its problems]
2. Description of the Related Art As a conventional mold clamping device for a hollow molding machine, for example, one described in Japanese Patent Application Laid-Open No. 11-42701 is known. As shown in FIG. 4 and FIG. 5, the moving table 30, a rod 19a, 19b slidably supported by the moving table 30, and a first mold fixed to one end of the rod 19a, 19b. Part 2, a second mold part 3 slidably supported by rods 19a and 19b, and a rear plate 18 at the other end of rods 19a and 19b and a second mold part 3, An opening / closing drive device 32 that opens the first mold part 2 and the second mold part 3 in the contracted state and closes the first mold part 2 and the second mold part 3 in the extended state; The first mold section 2 and the second mold section 3 are closed to hold the parison 6.
[0003]
Actually, the first mold part 2 is fixed to the front ends of the rods 19a and 19b via the connecting body 21 and the first mold holding body 17. Further, the second mold part 3 is slidably supported by the rods 19a and 19b via the second mold holder 10. 1a is a cavity of the mold 1 defined by the first mold part 2 and the second mold part 3. The parison 6 hangs from the crosshead 5 of the extruder 4. Reference numeral 22 denotes a guide bar for moving the entire mold clamping device in the left-right direction.
[0004]
The opening / closing drive device 32 has the toggle mechanism 9 and the electric motor 15. The toggle mechanism 9 is configured by connecting a pair of first and second toggle pieces 7 and 8 by a support shaft 11 so as to be freely bent, and is provided on a first bracket 7 a fixed to the second mold holder 10. The first toggle piece 7 is swingably pin-coupled, and the second toggle piece 8 is swingably pin-coupled to a second bracket 8 a fixed to the rear plate 18. The support shaft 11 is attached to the guide block 12. The guide block 12 is guided in a vertical direction (direction B in FIG. 4) by a pair of center positioning guide bars (not shown), and moves the pair of toggle pieces 7, 8 in a bent or straight line.
[0005]
That is, a guide screw that is screwed to the feed screw 16 by rotating the feed screw 16 such as a ball screw in the forward / reverse direction via the coupling 15 a by the electric motor 15 fixed to the movable base 30 and capable of driving in the forward / reverse direction. The block 12 reciprocates in the direction of the center axis of the guide bar fixed to the support portion 31 of the movable base 30. Then, as shown in FIG. 4, the first mold part 2 and the second mold part 3 are opened in the bent or contracted state of the toggle pieces 7, 8, and as shown in FIG. The first mold part 2 and the second mold part 3 are closed in a straight line, that is, in an extended state.
[0006]
With the first mold part 2 and the second mold part 3 closed, and the mold 1 holding the parison 6, the entire mold clamping device is moved in the left-right direction while being guided by the guide bar 22. As a result, the mold 1 is moved below the air blowing device 28 as shown in FIG. 6, the air blowing nozzle 28a is pressed against the upper surface of the mold, and air is blown into the parison 6 to perform blow molding.
[0007]
During the blow molding, the mold 1 is inclined. The cause of the mold 1 tilting is as follows. First, when the mold 1 is attached to the second mold holding body 10 and the first mold holding body 17, the own weight of the mold 1 acts on the rods 19a and 19b as a downward force to act on the rods 19a and 19b. Is bent downward.
[0008]
Next, when the mold 1 is closed as shown in FIG. 5, the output of the first toggle piece 7 acts on the second mold holder 10, and the output of the second toggle piece 8 is the rear plate. 18, acts on the rods 19a and 19b, the connector 21 and the first mold holder 17, and is transmitted to the mating surface of the mold 1 via the second mold holder 10 and the first mold holder 17, and Both the first mold part 2 and the second mold part 3 are tightened. The reaction force causes the rods 19a and 19b to bend and the connecting body 21 and the second mold holding body 10 to bend slightly, so that the mold 1 tilts forward (to the left in FIGS. 4 to 6).
[0009]
Further, after the mold 1 holds the parison 6, it moves below the air blowing device 28 as shown in FIG. 6 and presses the air blowing nozzle 28a against the upper surface of the mold. A downward force is applied. These three forces act on the rods 19a and 19b, and the rods 19a and 19b flex and deform. Accordingly, the mold 1 is inclined at the angle θ.
[0010]
As described above, due to the upward deformation of the rods 19a and 19b due to the own weight of the mold 1, the output of the opening / closing drive device 32, and the pressing force of the air blowing nozzle 28a, the mold 1 is moved downward. It sinks and tilts forward at an angle θ. Due to this, when the air blowing nozzle 28a is inserted into the upper part of the mold 1 to perform molding, the cut ring 28b of the air blowing nozzle 28a and the base 1b of the upper part of the mold 1 as shown in FIG. Since the gap A is generated due to poor adhesion, a defect occurs at the neck of the molded product. In particular, poor cutting of the burr on the neck occurs.
[0011]
When the mold 1 is opened after molding and the molded product is taken out from the mold 1, the bending strain of the mold clamping device including the rods 19a and 19b is released, and the first mold part 2 and the second mold part 3 are moved. Since it returns elastically to the original position, the displacement between the cavity 1a of the mold 1 and the molded product occurs, and the molded product is deformed. Accompanying this, a scratch is generated on the molded product, resulting in a defective product. In particular, the neck, shoulder, and bottom of the molded product are poorly scratched. In addition, when the mold is opened, the neck of the molded product is likely to bend.
[0012]
SUMMARY OF THE INVENTION An object of the present invention is to provide a mold clamping device for a hollow molding machine in which the above-mentioned various defective products are unlikely to occur, by suppressing the upwardly convex curved deformation of the rod and, by extension, the tilting of the mold.
[0013]
[Means for Solving the Problems]
The present invention has been made in view of such a conventional technical problem, and has the following configuration.
The configuration of the invention according to claim 1 includes a moving table 30, a rod 19a, 19b slidably supported by the moving table 30, and a first mold member (1) fixed to one end of the rod 19a, 19b. 2, 17, 21), a second mold member (3, 10) slidably supported by rods 19a, 19b, a rear plate 18 at the other end of the rods 19a, 19b, and a second mold member. (3, 10) and an opening / closing drive device 32 disposed between the first and second mold members (2, 17, 21) and the second mold member (3, 10). A mold clamping device for a hollow molding machine that holds
A movable base 43 that is integral with the movable base 30 is provided, and at least one of the lower surfaces of the first mold member (2, 17, 21) and the second mold member (3, 10) is attached to the support portion 44. This is a mold clamping device for a blow molding machine characterized in that it is supported on a movable base 43 so as to be movable in the front-rear direction via the movable base 43, thereby suppressing upwardly convex deformation of the rods 19a and 19b. The opening / closing drive unit 32 opens the first mold member (2, 17, 21) and the second mold member (3, 10) in the contracted state, and opens the first mold member (2, 17, 21) in the extended state. 21) and the second mold members (3, 10) are closed.
According to the configuration of the second aspect of the present invention, the movable die base 43 is supported by the fixed gantry 41 so as to be movable in the left-right direction, and the movable die base 43 moves with respect to the gantry 41, thereby the first mold member (2 , 17, 21) and the second mold member (3, 10) move between the receiving position I of the parison 6 and the air blowing position II. Device.
According to a third aspect of the present invention, the support portion 44 is formed by wheels, and the wheels roll on the movable base 43. Power device.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
The mold 1 has a pair of a first mold part 2 and a second mold part 3, and the mold parts 2, 3 can be opened and closed back and forth (left and right directions in FIGS. 1 and 2). A cylindrical parison 6 hanging from the crosshead 5 of the extruder 4 is supplied into the cavity 1 a of the mold 1. The second mold part 3 is fixed to the second mold holder 10, and the first mold part 2 is fixed to the first mold holder 17. The second mold holder 10 is slidably supported by rods 19a and 19b, which will be described later, in the mold opening and closing direction (front-back direction).
[0015]
The first mold part 2 and the second mold part 3 are driven to open and close by an opening and closing drive device 32. The opening / closing drive device 32 includes a toggle mechanism 9 including the guide block 12, an electric motor (not shown), a feed screw 16, and the like. The opening / closing drive device 32 allows the toggle mechanism 9 to switch between a bent state and an extended state. The mold 1 can be opened in a bent shape, and the mold 1 can be closed in an extended linear shape.
[0016]
The second mold part 3 is connected to one end of the toggle mechanism 9 via the second mold holder 10 and the first bracket 7a. The toggle mechanism 9 is formed by connecting a pair of first and second toggle pieces 7 and 8 by a support shaft 11 so that the first toggle piece 7 can swing freely on a first bracket 7a. Are combined. The support shaft 11 is fixed to the guide block 12. The guide block 12 is guided in a vertical direction (direction B in FIG. 2) by a guide bar fixed to the support portion 31 of the movable base 30, and the pair of toggle pieces 7, 8 are bent or linearly formed. Move. That is, by rotating the feed screw 16 such as a ball screw in the normal and reverse directions by a motor (not shown) capable of normal and reverse drive fixed to the movable base 30, the guide block 12 screwed to the feed screw 16 is rotated. Reciprocates in the B direction. The second mold part 3 and the second mold holder 10 constitute a second mold member.
[0017]
A rear plate 18 is connected to the other end of the toggle mechanism 9, that is, the second toggle piece 8 via a second bracket 8a. The second toggle piece 8 is swingably pin-connected to the second bracket 8a. The other ends of a pair of rods 19a and 19b are connected and fixed to the rear plate 18, and the intermediate portions of the rods 19a and 19b are slidably supported by the cylindrical support portions 30a and 30b of the movable base 30. The first mold holder 17 is attached to a connecting body 21 fixedly connected to one end thereof. Accordingly, the rear plate 18, the rods 19a and 19b, the connecting body 21, the first mold holder 17, and the first mold part 2 move forward and backward integrally. The mold 1 and the toggle mechanism 9 are located above the rods 19a and 19b. A first mold member is constituted by the first mold portion 2, the first mold holder 17, and the connecting body 21 including the front ends of the rods 19a and 19b. The above configuration is not substantially different from the mold clamping device of the conventional blow molding machine.
[0018]
The mold clamping device is movably mounted and supported on the gantry 41 via the movable base 43, and the movable base 43 is moved in the left-right direction with respect to the fixed gantry 41 (see FIG. 1 and FIG. 2). (In the vertical direction). The moving base 43 is fixed to the moving base 30 and is installed so as to be guided by a moving guide 45 provided on the gantry 41. Accordingly, the mold clamping device including the movable base 43 and the movable base 30 is moved from the receiving position I of the parison 6 shown in FIG. 3 to the air blowing position by the driving means 150 (such as an electric motor and a ball screw) installed on the base 41. Movement to II and vice versa is possible. The gantry 41 is formed in a range in which the mold clamping device can move between the receiving position I of the parison 6 and the air blowing position II. The moving guides 45 are arranged at a plurality of positions, and can be configured by, for example, a rail and a meshing block.
[0019]
By the movable base base 43 integrated with the movable base 30, at least one lower surface of the first mold member (2, 17, 21) and the second mold member (3, 10) is supported by the support portion. It is supported so as to be movable in the front-rear direction (the left-right direction in FIGS. 1 and 2) via 44. In the illustrated example, the movable base 43 is integrally fixed to the lower surface of the movable base 30, and a support portion 44 is provided on each of the lower surface of the connecting body 21 and the lower surface of the rear plate 18. It is supported on a movable base 43 via a support portion 44 so as to be movable in the front-rear direction. The support portion 44 can be formed by a single or plural slide bearings or rolling bearings provided on each of the connecting body 21 and the rear plate 18 or a rail and a meshing block. Move or engage. By supporting the rear plate 18 by the movable base 43, the posture of the rear ends of the rods 19a and 19b, and hence the posture of the mold clamping device, are stabilized.
[0020]
In the illustrated example, the support portion 44 is formed by wheels rotatably supported below the connecting body 21, the rear plate 18, and the like, and rolls on the movable base 43 in the front-rear direction by the wheels. Can be. The wheels may be single wheels or double wheels.
[0021]
Thus, the weight of the mold 1 acting on the front ends of the rods 19a and 19b, the downward pressing force resulting from the output of the toggle mechanism 9, and the pressing force of the air blowing nozzle 28a are all transmitted through the support portion 44. , Are supported by a rigid moving base 43 fixed to the moving base 30. Since the movable base 43 supports the entire mold clamping device and is supported on the fixed gantry 41 so as to be movable in the left-right direction, it is unlikely to be bent and deformed.
[0022]
Numeral 46 denotes an adjusting portion which adjusts the height of the support portion 44 such as wheels, prevents poor contact with the upper surface of the movable base 43, and provides a good close contact state. The adjusting portion 46 can be formed by a tapered slide plate, an adjusting screw, or the like.
[0023]
Next, the operation will be described.
By operating an electric motor (not shown) to rotate the feed screw 16 and move the guide block 12 along the guide bar, each of the toggle pieces 7 and 8 pushed and pulled by the support shaft 11 is moved. It has a bent shape shown in FIG. 2 or a straight shape shown in FIG. Each of the toggle pieces 7 and 8 is folded in a bent shape to open a pair of mold parts 2 and 3, and a cylindrical parison 6 hanging from the crosshead 5 of the extruder 4 is provided in the cavity 1 a of the mold 1. Then, the toggle pieces 7 and 8 are linearly extended, the pair of mold parts 2 and 3 are closed, and the parison 6 is held by the mold 1.
[0024]
When the mold 1 is closed, the pair of molds 2 and 3 gradually approach each other, and the molds 2 and 3 touch each other in a state where the toggle mechanism 9 takes a predetermined bending posture. The extension of 9 causes each of the toggle pieces 7 and 8 to extend in a straight line, and the mold is closed with a predetermined clamping force. When the mold 1 is opened and closed, the support portion 44 moves while sliding or rolling on the movable base 43.
[0025]
When the parison 6 having a predetermined length is held by the mold 1, the mold clamping device and the movable base 43 are moved on the gantry 41 from left to right in FIG. To II) and below the air blowing device 28 (air blowing position II) as shown in FIG. Next, the air blowing nozzle 28a is inserted into the upper part of the mold 1, the cut ring is pressed against the upper surface of the mold 1, and air is blown into the parison 6 to perform blow molding. When the blow molding is completed, the mold 1 is opened, the molded product is taken out, and the mold clamping device and the movable base 43 are moved on the gantry 41 from right to left (II to I) in FIG. At the receiving position I, the mold 1 receives the parison 6. By repeating such an operation, blow molding is performed continuously.
[0026]
The operation of the movable base 43 will be described. First, when the mold 1 is attached to the second mold holder 10 and the first mold holder 17, the own weight of the mold 1 acts on the rods 19a and 19b as a downward force. Since the own weight of 1 is supported on the movable base 43 via the support portion 44, the phenomenon that the front ends of the rods 19a and 19b hang downward and bend is suppressed. Thereby, forward tilting of the mold 1 is suppressed.
[0027]
Next, as shown in FIG. 1, when the mold 1 is closed and the mold 1 is closed, the output of the toggle pieces 7 and 8 is applied to the second mold holder 10, the rear plate 18, the rods 19a and 19b, the connecting body 21 and Although transmitted to the mating surface of the mold 1 via the first mold holding body 17, the two mold parts 2 and 3 are tightened, and the rods 19a and 19b which receive the reaction force tend to be curved upwardly convexly. The bending of the rods 19a and 19b is also suppressed by the rigid movable base 43 fixed to the rigid movable base 30. Thereby, the forward tilting of the mold 1 is suppressed, and the mold is closed with the mating surface of the mold 1 positioned at a predetermined center. However, the first mold holder 17, the connecting body 21, and the second mold holder 10 are slightly deformed. However, these are known to have negligible distortion due to the use of rigid members. That is, the largest distortion occurs in the rods 19a and 19b.
[0028]
Further, FIG. 6 also shows that when the mold 1 holds the parison 6 and then moves below the air blowing device 28 (air blowing position II) and presses the air blowing nozzle 28a against the upper surface of the mold 1. Similarly, a downward force is applied to the rods 19a and 19b, and the front ends of the rods 19a and 19b tend to bend downward. The bending of the rods 19a and 19b is also fixed to the movable base 30. It is suppressed by the base 43. Thereby, forward tilting of the mold 1 is suppressed. The movement of the mold clamping device including the movable base 43 and the movable base 30 is guided by a movable guide 45. If the moving guides 45 are provided at both front and rear ends of the movable base 43, the support and movement of the mold clamping device are stabilized.
[0029]
In this way, the upward deformation of the front ends of the rods 19a and 19b due to the own weight of the mold 1, the output of the opening / closing drive device 32, and the pressing force of the air blowing nozzle 28a causes the mold to be deformed. Sinking of the mold 1 downward and tilting forward is well suppressed, and the mating surface of the mold 1 is positioned at a predetermined center. As a result, when the air blowing nozzle 28a is inserted into the upper part of the mold 1 and molded, as shown in FIG. In addition, since the gaps A are less likely to be generated due to good adhesion, the upper burr is cut and separated well. As a result, it is possible to prevent the occurrence of a defect at the neck portion of the molded product due to the defective burr cutting.
[0030]
Furthermore, since there is almost no elastic bending strain in the mold clamping device, when the molding is completed and the mold 1 is opened and the molded product is taken out from the mold 1, the mold clamping device is elastically deformed and restored. And there is almost no displacement between the cavity 1a of the mold 1 and the molded product. For this reason, generation of scratches on the neck, shoulder, and bottom due to deformation of the molded product can be prevented.
[0031]
The suppression of the tilting of the mold 1 accompanying the sinking of the mold 1 in the forward direction is achieved by the front end portions of the rods 19a and 19b projecting forward from the movable base 30 in the mold-clamped state, that is, the first mold portion 2 and the first mold. This can be effectively obtained by supporting the lower surfaces of the mold holder 17 and the connecting member 21 by the movable base 43, but only the lower surfaces of the second mold part 3 and the second mold holder 10 are supported by the movable base. Even if it is supported by 43, the effect of suppressing the forward tilt of the mold 1 can be obtained. Of course, if both are supported by the movable base 43, the effect of suppressing the forward tilt of the mold 1 can be obtained well. If the lower surface of the rear plate 18 is supported by the movable base 43, the support of the mold clamping device to the gantry 41 is stabilized.
[0032]
By the way, in the above embodiment, the opening / closing drive device is provided with the toggle mechanism 9, but the opening / closing drive device is disposed between the rear plate 18 and the second mold portion 3, and is in a contracted state. The first mold part 2 and the second mold part 3 may have a function of opening the mold and closing the first mold part 2 and the second mold part 3 in the extended state. May be provided.
[0033]
【The invention's effect】
As will be understood from the above description, the following effects can be obtained by the mold clamping device of the blow molding machine according to the present invention.
A movable base integrated with the movable base is provided, and at least one of the lower surfaces of the first mold member and the second mold member is supported by the movable base via the support portion so as to be movable in the front-rear direction, The upward convex deformation of the rod was suppressed. Thereby, the forward tilt of the mold is suppressed, and the mold moves so that the mating surface of the mold is located at the predetermined center.
[0034]
As a result, when the air blowing nozzle is inserted into the mold and the cut ring is brought into close contact, the neck of the molded product can be cut off satisfactorily. In addition, when the mold is opened, the neck of the molded product is less likely to bend, and the abrasion of the neck, shoulder, bottom and the like of the molded product is also eliminated. In addition, when the mold has a blade at the bottom, there is no displacement of the blade, and the burr of the parison at the bottom at the time of closing the mold is good. As a result, it is possible to obtain a molded product having good quality.
[0035]
According to the invention according to claim 2, the movable base is supported by the fixed gantry so as to be movable in the left-right direction, and the movable base moves relative to the gantry. As described above, if the movable base is supported by the fixed base, deformation of the movable base can be favorably suppressed. As a result, the upwardly convex deformation of the rod, and thus the forward tilting of the mold, can be more favorably suppressed, and a molded product of good quality can be obtained.
[Brief description of the drawings]
FIG. 1 is a side view showing a closed state of a mold clamping device of a blow molding machine according to one embodiment of the present invention.
FIG. 2 is an operation explanatory view showing a mold opening state.
FIG. 3 is a front view of the same.
FIG. 4 is a side view showing a mold opening state of a mold clamping device of a conventional hollow molding machine.
FIG. 5 is a side view showing the mold closed state.
FIG. 6 is an operation explanatory view of the same mold closed state.
FIG. 7 is an explanatory view showing a state where an air blowing nozzle is inserted into a mold of the hollow molding machine.
[Explanation of symbols]
1: mold, 2: first mold part (first mold member), 3: second mold part (second mold member), 6: parison, 9: toggle mechanism, 10: second mold Holder (second mold member), 17: first mold holder (first mold member), 18: rear plate, 19a, 19b: rod, 21: connector (first mold member), 30 : Moving table, 32: open / close drive, 41: frame, 43: moving table base, 44: support, I: receiving position, II: air blowing position.

Claims (3)

A moving table (30), a rod (19a, 19b) slidably supported by the moving table (30), and a first mold member (2, 2) fixed to one end of the rod (19a, 19b). 17, 21), a second mold member (3, 10) slidably supported by the rods (19a, 19b), a rear plate (18) at the other end of the rods (19a, 19b), and a second mold member. An opening / closing drive (32) disposed between the first mold member (2, 17, 21) and the second mold member (3, 10). A mold clamping device for a blow molding machine for holding a parison (6) by closing the mold,
A movable base (43) integral with the movable base (30) is provided, and at least one lower surface of the first mold member (2, 17, 21) and the second mold member (3, 10) is A mold clamping device for a hollow molding machine, which is supported on a movable base (43) via a support portion (44) so as to be movable in the front-rear direction and suppresses upward deformation of the rods (19a, 19b). . The movable base (43) is supported by a fixed mount (41) so as to be movable in the left-right direction, and the movable base (43) moves relative to the mount (41), whereby the first mold member (2, 2). 17. The blow molding of claim 1, wherein the second mold member (17, 21) and the second mold member (3, 10) move between a receiving position (I) of the parison (6) and an air blowing position (II). Machine clamping force device. 3. A clamping device for a blow molding machine according to claim 1, wherein the support part (44) is formed by wheels, and the wheels roll on a carriage base (43).

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