JPH11129303A - Method and apparatus for tie bar lock of composite straight-hydraulic mold clamping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for tie bar lock capable of preventing biting failures relative to the tie bar screw of a half nut in the tie bar lock device. SOLUTION: The other ends of links 16 rotatably affixed respectively to a pair of half nuts 13a, 13b of a tie bar lock device are connected by guide pins 17 being movable only in the center of a tie bar 4 and in the longitudinal direction thereof, and a cylinder 15 attached to a movable disk 2 is secured to one half nut 13a to operate; then allowing both the half nuts 13a, 13b to open and close relative to the tie bar 4 in synchronization with its diameter direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tie bar locking method for a composite direct pressure type mold clamping device used in a composite direct pressure type injection molding machine and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, in a mold clamping device used for an injection molding machine or a die casting machine, a mold opening / closing cylinder is used for opening and closing a mold instead of a hydraulic direct pressure type and a toggle type clamping device for the purpose of speeding up and reducing the weight. There is known a so-called composite direct pressure type mold clamping device in which the mold clamping and releasing are performed at a high pressure and a low speed by a mold clamping cylinder.

FIG. 4 shows an example of the mold clamping device. As shown in the figure, a fixed board 1 is fixed to a bed (not shown). A plurality of tie bars 4 are supported on the fixed plate 1 so as to be slidable in the axial direction, respectively, and one ends of the tie bars 4 are connected by a connecting plate 3. A tie bar screw 4 a is formed at the center of the tie bar 4. Fixed board 1 and connecting board 3
In between, the movable platen 2 is slidably guided by the tie bar 4,
The tie bar lock device 21 is reciprocated at a high speed by the mold opening / closing cylinder 6 and provided integrally with the movable platen 2.
By opening and closing the half nuts 23a and 23b of
The tie bar screw 4a is engaged or released.

On the other hand, the other end of the tie bar 4 is connected to a mold clamping piston 5a of a mold clamping cylinder 5, and supplies pressure oil to the left or right chamber of the mold clamping cylinder 5 in the drawing. Thereby, it is configured to be reciprocated in the axial direction.

In the mold clamping step, first, the mold opening / closing cylinder 6 is driven to move the movable platen 2 toward the fixed platen 1 at high speed.
In the middle of the stroke of the mold opening / closing cylinder 6, the operation of closing the half nuts 23a and 23b is started so that the mold opening / closing cylinder 6 is completely locked when the stroke limit is reached, and then the mold clamping cylinder 5 is driven. Perform mold clamping at high pressure. FIG. 4 shows a state in which the mold clamping is completed.

FIG. 5 is a sectional view of a main part of the tie bar lock device. In the figure, a guide cover 22 is attached to the movable platen 2 for each tie bar 4, and a pair of half nuts 23 a and 23 b facing each other around the tie bar 4 are slidably provided on the guide cover 22. I have. Half nuts 24a, 24b, which are engagement projections, are formed on the inner surfaces of the half nuts 23a, 23b.

The tip of the piston rod 25a of the cylinder 25 is attached to the left half nut 23a in the figure, and the right half nut 23b is implanted on a plate 26 attached to the tip of the cylinder 25. A rod 27 extending through the half nut 23a is attached.

Next, the operation will be described. (a) When the cylinder 25 is driven to extend the piston rod 25a, the left half nut 23a is pushed and moves in the direction of the tie bar 4. (b) The reaction force when the cylinder 25 pushes the left half nut 23a moves the cylinder 25 itself to the left. (c) Thereby, the right half nut 23b connected to the cylinder 25 via the plate 26 and the rod 27
Moves to the left, that is, in the direction of the tie bar 4. (d) The half nut nuts 24a and 14b provided on the half nuts 23a and 23b are engaged with the tie bar screws 4a formed at the central portion of the tie bar 4, and the tie bar 4 is locked.

[0009]

If the above-mentioned tie-bar lock device is in an ideal state, it is considered that both half nuts lock the tie bar at the same time. Either half nut starts to move and contacts the tie bar screw. Then, the other half nut starts moving and locks the tie bar. As described above, since the tie bar cannot be locked at the same time on the left and right sides, a biting failure of the half nut with respect to the tie bar screw occurs, and in many cases, the tie bar cannot be completely locked or the half nut does not come off even if locked. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a tie-bar lock method and a tie-bar lock method which can prevent a half nut of a tie-bar lock device from biting into a tie-bar screw. That is the task.

[0011]

The present invention has solved the above-mentioned problems as follows. That is, the other end of the link provided rotatably on the pair of half nuts of the tie bar lock device of the direct pressure injection molding machine is connected to the center of the tie bar,
It is connected with a guide pin that moves only in the longitudinal direction, and the opening and closing means attached to the movable platen is attached to one half nut to operate, and both half nuts are opened and closed in synchronization with the tie bar in the radial direction, The engaging protrusion of the nut and the engaging protrusion of the tie bar are synchronously engaged or released.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings.

As shown in FIG. 1, a composite direct pressure type mold clamping device of a direct pressure type injection molding machine has a fixed platen 1 on which a fixed die 1a is mounted on a bed (not shown).
A plurality of tie bars 4 are respectively supported on the fixed platen 1 so as to be slidable in the axial direction. Each tie bar 4 has a tie bar screw 4a of a predetermined pitch, which is an engagement projection of the tie bar 4 formed at a substantially central portion thereof, and a fixed plate side end protruding from the fixed plate 1 is integrated with the fixed plate 1. Is connected to a mold clamping piston 5a of a mold clamping cylinder 5 provided at
The other end of each tie bar 4 is connected by a connection board 3. The two chambers on both sides of the mold closing piston 5a of the mold closing cylinder 5 are provided with one conduit 9a in which the direction of the flow of pressure oil discharged from the pump 8 is switched by an electromagnetic valve 7 switched by a signal from a controller (not shown). The other pipes 9b are communicated with each other, and the mold clamping piston 5a
The tie bar 4 can be reciprocated in the axial direction integrally with the mold clamping piston 5a by supplying the pressure oil to the chambers on both sides of the tie bar. A movable plate 2 to which a movable mold 2a is attached is guided between the fixed plate side of the tie bar 4 and the connecting plate so as to be slidable in the axial direction. Are connected to each other via a rod so that the mold can be closed and opened at high speed.

FIG. 2 is a sectional view of a main part of the tie bar lock device according to the present invention. FIG. 2 (a) is a sectional front view of the main part, and FIG. 2 (b) is a side view of FIG. 2 (a). 1 and 2
As shown in FIG. 2, a guide cover 12 is attached to the movable platen 2 for each tie bar 4, and a pair of half nuts 13 facing each other around the tie bar 4 are attached to the guide cover 12.
a and 13b are slidably provided. Half nut screws 14a, 14b as engagement projections are formed on the inner surfaces of the half nuts 13a, 13b.

In FIG. 2 (a), the left half nut 13a
, The tip of a piston rod 15a of a cylinder 15 attached to the movable platen 2 is attached. A link 16 having a fulcrum at a position parallel to the center axis of the piston rod 15a is rotatably mounted on the upper and lower surfaces of the left half nut 13a and the right half nut 13b, and the other ends of the two links 16 are guide pins. It is tied at 17. The guide cover 12 is provided with an elongated hole 18 so that the guide pin 17 can move only in the center of the tie bar 4 and in the longitudinal direction.

Next, the operation will be described with reference to FIG. (a) When the cylinder 15 is driven to contract the piston rod 15a, the left half nut 13a and the right half nut 13b are separated by the link 16 and the guide pin 17, as shown in FIG. The half nut screws 14a and 14b and the tie bar screw 4a are disengaged from each other in synchronization with each other. (b) When the cylinder 15 is driven to extend the piston rod 15a, as shown in FIG. 3B, the link 16 and the guide pin 17 cause the left half nut screw 13a to move.
The half nut 13b on the right side and the right half nut 13b move synchronously in the approaching direction, the half nut screws 14a and 14b engage with the tie bar screw 4a, and the tie bar 4 is locked.

As described above, the half nuts 13a and 13b of the tie bar lock device 11 are opened and closed synchronously in the radial direction with respect to the tie bar 4 by the cylinder 15 as opening / closing means, so that the half nuts formed on the opposing surface. 1
Half nut screw 14 which is an engagement projection of 3a, 13b
The tie bar screw 4a, which is the engagement projection between the tie bar 4 and the tie bar 4, can be securely engaged or released.

[0018]

According to the present invention, since both half nuts can be moved synchronously with respect to the tie bar, defects due to the half nuts biting into the tie bar can be eliminated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a composite direct pressure type mold clamping device to which the present invention is applied.

2 is a configuration diagram of a tie bar lock device according to the present invention, FIG. 2 (a) is a cross-sectional front view of a main part, and FIG. 2 (b) is FIG.
It is a side view of (a).

FIG. 3 is a view taken along line AA of FIG. 2 (a), showing the operation of a half nut. FIG. 3A shows a state in which the half nut is open, and FIG. 3B shows a state in which the half nut is closed.

FIG. 4 is a configuration diagram of a conventional composite direct pressure type mold clamping device.

FIG. 5 is a configuration diagram of a conventional tie bar lock device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed board 1a Fixed mold 2 Movable board 2a Movable mold 3 Connecting board 4 Tie bar 4a Tie bar screw 5 Mold clamping cylinder 5a Mold clamping piston 6 Mold opening and closing cylinder 6a Piston 7 Solenoid valve 8 Pump 9a, 9b Pipe line 11 Tie bar lock device 12 Guide cover 13a, 13b Half nut 14a, 14b Half nut screw 15 Cylinder 15a Pinton rod 16 Link 17 Guide pin 18 Slot

Claims (2)

[Claims] 1. A movable platen (2) attached with a movable mold (2a) and guided by a plurality of tie bars (4) is moved toward a fixed platen (1) on which a fixed mold (1a) is attached. A composite direct pressure type mold clamping device that moves and closes the mold, locks the movable plate (2) and the tie bar (4) with a tie bar lock device (11) attached to the movable plate (2), and then clamps the mold. In the tie bar locking method, the other end of the link (16) rotatably attached to the pair of half nuts (13a, 13b) of the tie bar locking device (11) is connected to the center of the tie bar (4) in the longitudinal direction. The opening / closing means (15) attached to the movable platen (2) is attached to one half nut (13a) for operation, and both half nuts (13a, 13b) are connected. Tie bar locking method of a composite direct pressure type mold clamping apparatus characterized by synchronizing to open and close in the radial direction relative to the bar (4). 2. A movable platen (2) attached with a movable mold (2a) and guided by a plurality of tie bars (4) is moved toward a fixed plate (1) to which a fixed mold (1a) is attached. A composite direct pressure type mold clamping device that moves and closes the mold, locks the movable plate (2) and the tie bar (4) with a tie bar lock device (11) attached to the movable plate (2), and then clamps the mold. In the tie bar lock device, the tie bar lock device (11) includes a guide cover (1) attached to the movable platen (2) for each tie bar (4).
2), a pair of half nuts (13a, 13b) slidably provided in the guide cover (12) and opened and closed in the radial direction with respect to the tie bar (4), and attached to the movable platen (2). A cylinder (15) having a piston rod (15a) attached to one of the half nuts (13a, 13b), and both half nuts (13a, 13b);
And a link (16), one end of which is rotatably mounted on the sliding surface and the other end of which is connected by a guide pin (17). The guide cover (12) has a guide pin (17). A tie bar locking device for a compound direct pressure type mold clamping device, characterized by being provided with an elongated hole (18) that can move only in the center of the tie bar (4) and in the longitudinal direction.