JP3484024B2 - Mold clamping device for blow molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for a hollow molding machine, and more particularly to a toggle type mold clamping device for a hollow molding machine.

[0002]

2. Description of the Related Art Conventionally, as a toggle type mold clamping device for a hollow molding machine, a structure shown in FIG. 4 has been generally adopted. In the figure, the front die mounting plate 31 and the rear plate 32 are connected by a tie bar 33 with a certain distance.
A rear mold mounting plate 34 is provided opposite to the front mold mounting plate 31 so as to be movable back and forth via a tie bar 33. A single toggle device 35 is attached to the rear die mounting plate 34 and the rear plate 32.

The single toggle unit 35 has a first end pivotally attached to the rear die mounting plate 34 via a toggle pin 38.
Link member 36 and the rear die mounting plate 32 with toggle pin 39
The second link pin 37 is pivotally attached at one end through the link pin 36, and the other ends of the link members 36 and 37 are connected via a toggle pin 40. In addition, this toggle pin 4
A hydraulic cylinder 41 is connected to 0 via a clevis. Instead of the single toggle device 35 described above, FIG.
As shown in (a), there is a double toggle device 42 in which the single toggle device 35 shown in FIG.

[0004]

Since the conventional toggle type mold clamping device for the hollow molding machine is constructed as described above, the following problems exist. (a) In the case of the single toggle device, as shown in FIG. 4, the driving force P for generating the mold opening / closing force moves the mold in the driving force acting direction to shift the mold, and the burr cutting force is dispersed, The cutting power cannot be used effectively. (b) In case of the double toggle device, two driving sources are required. Further, as shown in FIG. 5B, since it is a three-bar linkage system, the ratio of the die opening / closing stroke amount b to the driving stroke amount a is small. (c) Since a hydraulic cylinder is used to drive the toggle link, the cleanliness will be reduced if a blow molding machine is used in a clean room. (d) When maintaining the mold clamping force, a relatively large driving force is required, resulting in a loss of driving energy.

The present invention has been made in view of the above problems, and is provided with a toggle device in which the ratio of the die opening / closing stroke amount to the driving stroke amount is large and the burrs are well cut off. It is an object of the present invention to provide a mold clamping device for a hollow molding machine, the thickness of which can be adjusted continuously.

[0006]

The present invention has solved the above problems as follows. That is, between the front mold mounting plate and the rear plate connected by the tie bar, the rear mold mounting plate and the mold clamping housing are provided so as to be movable back and forth through the tie bar.
Attach the double toggle device dowel link to the rear die mounting plate and the die clamping housing, attach the synchronizer to the rear die attaching plate and the rear plate, and further attach the die thickness adjusting screw machined to one end of the tie bar on the die clamping housing. A rotatably mounted screw member for adjusting the mold thickness that is screwed into The toggle link is connected to a ball screw via a crosshead, and the ball screw is screwed to a ball nut rotatably attached to the mold clamping housing. Further, the mold thickness adjusting screw member and the ball nut are rotationally driven by an electric motor.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A mold clamping device for a blow molding machine according to the present invention includes a rear mold mounting plate and a mold clamping housing via a tie bar between a front mold mounting plate and a rear plate connected by a tie bar. A double toggle device is attached to the rear mold mounting plate and the mold clamping housing, and a synchronizing device is mounted to the rear mold mounting plate and the rear plate.

The toggle link of the double toggle device is
It is preferably a 5-section link.

Further, the toggle link is connected to a ball screw via a crosshead, and the ball screw is screwed into a ball nut rotatably attached to the mold clamping housing, and the ball nut is rotationally driven by an electric motor. Preferably.

Further, a male screw for adjusting the mold thickness is machined at one end of the tie bar, and a female screw for adjusting the mold thickness rotatably attached to the mold clamping housing is screwed onto the male screw for adjusting the mold thickness. It is preferable that the mold thickness adjusting female screw is rotationally driven by an electric motor.

[0011]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of a double toggle type mold clamping device of a hollow molding machine.

In the figure, the front die mounting plate 1 and the rear plate 2 are
They are connected by a tie bar 3 with a certain distance. A rear mold mounting plate 4 is provided so as to face the front mold mounting plate 1 so as to be movable back and forth via a tie bar 3. A mold clamping housing 5 is provided between the rear mold mounting plate 4 and the rear plate 2 so as to be movable back and forth via a tie bar 3.

A double toggle device 6 is attached to the rear die mounting plate 4 and the die clamping housing 5.

The tab toggle mechanism 6 includes a first link member 7, one end of which is pivotally attached to the rear mold mounting plate 4 via a toggle pin 11, the other end of the first link member 7 and the mold clamping housing 5, each of which has a toggle pin 12. Second pivotally attached via
5 link toggle link 16 comprising a third link member 10 pivotally attached to side portions of the link member 8 and the second link 8 and the crosshead 9 via toggle pins 14 and 15, respectively.
And a drive unit 17 that directly moves the crosshead 9.

The drive unit 17 is provided in the axial direction of the mold clamping device and operates a toggle link 16 via a crosshead 9 to move the front and rear mold mounting plates 1 and 4 in a contacting and separating direction, and a ball screw 18. A ball nut 19 which is rotated by an electric motor (not shown) to move the ball screw 18 back and forth;
It is composed of a support member 20 attached to the rear surface of the mold clamping housing 5 and holding the ball nut 19 via a bearing. The toggle link 16 described above is double mounted on the cross head 9 in the vertical direction.

A mold thickness adjusting screw 21 is formed on one end of the tie bar 3, and the mold thickness adjusting screw member 2 rotatably attached to the rear surface of the mold clamping housing 5 is attached to the screw 21.
2 is screwed together. The mold thickness adjusting screw member 22 is
A common electric motor provided for each tie bar 3 rotates by a chain or a drive shaft, whereby the mold clamping housing 5 moves back and forth. The mold thickness adjusting screw member 22
The outer peripheral portion of is usually a worm gear. That is, the mold thickness adjusting screw 26, the mold thickness adjusting screw member 22, and the like form a mold thickness adjusting device 26.

Synchronous racks 23 are provided on the rear die mounting plate 4 and the rear plate 2 so as to face each other in the axial direction, and both synchronous racks 23 are screwed with a pinion 24 provided at a predetermined position. . That is, the synchronous rack 23 and the pinion 24
The synchronizer 25 is configured by the above. This synchronizer 2
Two sets of right and left 5 are normally provided below the lower toggle link 16.

Next, the operation of the double toggle device 6 described above will be described with reference to FIG.

As shown in FIG. 2, when the ball screw 18 is retracted, the synchronizer 25 advances the front mold mounting plate 1, the mold clamping housing 5 and the rear plate 2 by the dimension L to the positions 1 ', 5'. And 2'and the rear die mounting plate 4 has a dimension L.
It moves backward by a minute and moves to position 4 '.

That is, with the pinion 24 of the synchronizer 25 as a fixed point, each member makes a stroke of L by the operation of the toggle link 16 and the center of mold clamping does not change. Also, the gap between the two mold mounting plates 1 and 4 has changed by 2L. That is, the ratio of the die opening / closing stroke amount to the driving stroke amount becomes large. Further, since the toggle link 16 is provided in the upper and lower double, the mold clamping force effectively acts on the upper and lower burr portions.

Next, the operation of the mold thickness adjusting device 26 described above will be described with reference to FIG.

When the mold thickness adjusting screw member 22 is turned and the mold clamping housing 5 is stroked by S, regardless of the stroke (constant) of the toggle link 16, the mold thickness T0 is changed to the mold thickness T1 (T0-2 × S). ) Can be changed to.

[0024]

Since the present invention is constructed as described above, the following effects can be obtained. (a) Since the mold clamping force effectively acts on the upper and lower burrs, the burrs are well cut off. (b) The ratio of the die opening / closing stroke amount to the driving stroke amount can be increased. (c) Since the driving force required to maintain the mold clamping force is small, it is easy to use an electric servomotor, which enables energy saving and cleanliness. (d) The mold thickness can be adjusted steplessly.

[Brief description of drawings]

FIG. 1 is a schematic view of a double toggle type mold clamping device of a hollow molding machine according to the present invention.

FIG. 2 is an operation diagram of a mold clamping device.

FIG. 3 is an operation diagram of the mold thickness adjusting device.

FIG. 4 is a schematic view of a conventional single toggle device.

5 is a schematic view of a conventional double toggle device, FIG.
FIG. 5A shows a toggle link of three-section link system, and FIG.
(B) is a diagram showing a ratio of a drive stroke amount and a mold opening / closing stroke amount.

[Explanation of symbols]

1 Front die mounting plate 2 Rear plate 3 tie bars 4 Rear mold mounting plate 5 Mold clamping housing 6 double toggle device 7 First link member 8 Second link member 9 crosshead 10 Third link member 11, 12, 13, 14, 15 toggle pins 16 Toggle link 17 Drive 18 ball screw 19 Ball nut 20 Support member 21 Mold thickness adjusting screw 22 Screw thickness adjusting screw 23 Sync Rack 24 pinion 25 synchronizer

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 49/56 B29C 49/78

Claims (4)

(57) [Claims] 1. A rear mold mounting plate (4) and a mold clamping housing via a tie bar (3) between a front mold mounting plate (1) and a rear plate (2) connected by a tie bar (3). (5) is provided so as to be movable back and forth, and a double toggle device (6) is attached to the rear mold mounting plate (4) and the mold clamping housing (5), and the rear mold mounting plate (4) and the rear plate (2) are attached. ), A synchronizing device (25) is attached to the mold clamping device of the blow molding machine. 2. The mold clamping device for a hollow molding machine according to claim 1, wherein the toggle link (16) of the double toggle device (6) is a five-bar link. 3. The toggle link (16) is connected to a ball screw (18) via a crosshead (9), and the ball screw (18) is a ball rotatably attached to a mold clamping housing (5). Screwed onto the nut (19),
The mold clamping device for a hollow molding machine according to claim 1 or 2, wherein the ball nut (19) is rotationally driven by an electric motor. 4. A mold thickness adjusting screw (21) is processed at one end of the tie bar (3), and the mold thickness adjusting screw (21).
A mold thickness adjusting screw member (22) rotatably attached to the mold clamping housing (5) is screwed onto the mold clamping housing (5), and the mold thickness adjusting screw member (22) is rotationally driven by an electric motor. The mold clamping device for a hollow molding machine according to claim 1, 2, or 3.