JPH05228940A - Mold clamping device for molding machine - Google Patents

Abstract

PURPOSE:To carry out the adjustment of height of a die, make a working space on the rear face of movable platen wide without protruding a tie bar from the rear face of the movable platen at the time of mold clamping and simultaneously make a mold clamping device small and compact. CONSTITUTION:A die height adjusting nut 20 is installed on an inserting section of a die bar 18 of a fixed platen 14 and a screw section 22 screwing the nut is formed and installed on the outer periphery of the tie bar 18. A mold clamping ram 42 for running through the tie bar 18 is mounted on a movable platen 16 and a split nut 54 provided with a stopper flange being in contact with an end face of the tie bar 18 running through the ram 42 driven in the diameter direction of the tie bar 18 and fixing the tie bar 18 is installed. The die bar 18 is moved forward and backward by rotating the adjusting nut to adjust the die height, and the tie bar 18 is never running through and protruding from the movable platen at the time of mold clamping.

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 molding machine, and more particularly to a mold clamping device used for an injection molding machine, a die casting machine, a press molding machine or the like.

[0002]

2. Description of the Related Art Generally, in an injection molding machine, a die casting machine, or a press molding machine, a fixed mold and a moving mold are brought close to each other to perform mold matching, and thereafter, mold clamping is performed by a mold clamping cylinder device. There is. In order to perform this mold clamping operation, a fixed plate to which a mold is attached and a movable plate are connected by a tie bar, and one end of the tie bar constitutes a mold clamping cylinder device.

In such a mold clamping apparatus, the operations to be applied to the mold are a movement for mold matching which does not require a pressing force and a mold clamping operation which requires a strong pressing force for clamping. If the operation is burdened on the mold clamping cylinder device, the hydraulic system will become large, so normally an approach cylinder device (also called a moving cylinder or boost cylinder device) that is responsible for movement for mold matching separately from the mold clamping cylinder device. Is provided. As a result, the mold fitting operation with a long moving stroke is performed by the approach cylinder device, and after the mold matching, the mold clamping cylinder device performs mold clamping that requires a strong reduction force.

By the way, when exchanging a die having a different die thickness, the die height is adjusted to adjust the meshing position of the split nuts. This adjustment is performed by attaching a stopper in the middle of the tie bar and adjusting the position of the ring to adjust the position until it comes into contact with the movable platen. Also, as disclosed in Japanese Patent Laid-Open No. 60-212320, there has been proposed a structure in which a stopper mechanism is formed on the back surface of a movable plate in order to prevent the strength from being lowered by providing a stopper in the middle of the tie bar. There is.

[0005]

However, in the conventional mold clamping device, one end of the tie bar has a ram integral structure in which the mold clamping cylinder is mounted on the fixed platen, and the other end penetrates the movable platen. Since the structure is fixed with a half nut at the clamping position, the tie bar is projected from the back surface of the movable plate at the mold clamping position, and the work space for accessing the extrusion device etc. installed on the rear side of the movable plate is reduced. In addition to being limited, there is a problem that the length of protrusion of the tie bar from the movable plate becomes long and the mold clamping device becomes large. Further, since the mold clamping cylinder is provided with the mold thickness adjusting mechanism, there is a drawback that the mold clamping cylinder becomes large.

An object of the present invention is to pay attention to the above-mentioned conventional problems and to easily perform die height adjustment, and to prevent the tie bar from protruding from the back surface of the movable plate at the time of mold clamping. The purpose of the present invention is to obtain a compact and space-saving mold clamping device having a structure that can widen the working space of the mold and at the same time realize downsizing of the mold clamping device.

[0007]

In order to achieve the above object, in a mold clamping device of a molding machine according to the present invention, a fixed plate to which a fixed mold is mounted and a movable plate to which a movable mold is mounted are connected by a tie bar. In the mold clamping device of the molding machine, in which the mold clamping cylinder device is used to perform mold clamping, the die height adjusting nut is attached to the tie bar insertion part of the fixed plate, and the screw part screwed to this is attached to the outer peripheral surface of the tie bar. Engraved,
A mold clamping ram that penetrates the tie bar is mounted on the movable plate, and a split nut that has a stopper flange that abuts the end surface of the tie bar that penetrates the ram and is driven in the tie bar radial direction to fix the tie bar is attached. Is.

[0008]

According to the above construction, when the mold closing movement is performed for the mold clamping, the tie bar penetrates the mold clamping ram of the movable plate and contacts the stopper flange of the split nut to be positioned at the mold clamping position. In this state, the split nut is closed to complete the connection between the movable plate and the tie bar, so that the mold clamping is completed by supplying the hydraulic pressure to the mold clamping cylinder. At this time, since the tie bar does not project to the back surface of the movable plate, the work space for accessing the pushing device and the like is wide. The die height adjustment that is performed along with the die replacement is performed by rotating the die height adjusting nut attached to the fixed platen, and thereby the tie bar moves back and forth with respect to the fixed platen. At the minimum die height adjustment position, the amount of tie bar protrusion to the back of the fixed plate is the maximum, but since there is no protrusion to the back of the movable plate, it does not affect the work space to the back of the movable plate, and the conventional stopper As compared with the case of using the positioning mechanism according to, the space can be saved significantly, and the entire structure of the mold clamping device can be downsized.
Further, since the die height can be easily adjusted by rotating the adjusting nut, the operability is very simple.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a mold clamping device such as an injection molding machine according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a molding machine such as an injection device equipped with a mold clamping device according to the embodiment. As shown in this figure, the molding machine mounts a fixed mold 10 and a movable mold 12 on a fixed platen 14 and a movable platen 16, respectively. The fixed platen 14 is fixed to a base (not shown), while the movable platen 16 is slidably installed on the base and can move toward and away from the fixed platen 14. Four tie bars 18 are attached to the four corners of the outer edge of the fixed platen 14 and the movable platen 16 in order to support the movement guide of the movable platen 14 and the pressing force at the time of mold clamping.

Each tie bar 18 is fixedly supported on the stationary platen 14, and the supporting position is at the mold 1.
It can be changed depending on the laminated thickness (die height) of 0 and 12. That is, the die height adjusting nut 20 is rotatably attached to the tie bar insertion portion on the back surface of the fixed platen 14, while the screw portion 22 screwed to the nut 20 is engraved on the outer peripheral surface of the tie bar 18. ing. The nut 20 is held at a fixed position on the fixed platen 14 by the pressing plate 24 and its movement in the axial direction is regulated. By rotating the nut 20, the tie bar 18 can be moved forward and backward. In order to drive the nut 20 to rotate, a chain sprocket 26 is attached to an outer end portion of the nut 20, and a chain 28 wound around the chain sprocket 26 is also wound around a sprocket of the nut 20 screwed to another tie bar. The nut 20 is simultaneously rotated by a drive motor (not shown). Further, the fixed platen 14 is provided with a rotation stopping means 30 for the tie bar 18, which is constituted by a roller 34 attached to the fixed platen 14 and facing the tie bar insertion hole 32, as shown in FIG. A guide groove 36 into which the roller 34 is fitted is formed along the axial direction on the side of the tie bar 18, and the roller 34 held at a fixed position is fitted into the guide groove 36 so that the tie bar 18 is axially moved. It regulates it so that it can only move. As a result, the protruding length from the fixed platen 14 toward the movable platen 16 can be adjusted steplessly according to the height dimension of the molds 10 and 12 at the time of mold matching, that is, the so-called die height, and the set length can be adjusted nut. By stopping the rotation of 20, it can be kept constant.

On the other hand, the other end of the tie bar 18 is adapted to be inserted into the movable platen 16, which is passed through the mold clamping cylinder device 38 mounted on the movable platen 16. That is, the movable platen 16 has a tie bar 1
Forming a cylinder body 40 centered on the through portion of 8,
A ram 42 is slidably mounted inside this. The cylinder body 40 is provided with pressure oil supply / discharge ports 44, 46 so that the ram 42 can be driven back and forth by supplying / discharging hydraulic pressure. A tie bar through hole 48 is formed in the center of the ram 42, and a boss 50 projecting from the back surface of the movable plate 16 is extendedly formed especially on the back surface of the ram.

A split nut mechanism 52 is provided on the movable plate 16 so that the end portion of the tie bar 18 protruding from the through hole 48 can be held. As shown in detail in FIG. 4, this has a pair of split nuts 54R, 54L which are arranged so as to face the ram boss 50 of the mold clamping cylinder device 38 and which are split openable to the left and right,
An opening / closing operation is performed by an opening / closing cylinder 56 arranged on the side of one of the split nuts 54L. That is, the opening / closing cylinder 56 is supported by the mounting plate 58 so as to face the side surface of one split nut 54L.
The piston rod 60 is connected to the nearest split nut 54L, and the other split nut 54R has a plurality of operating rods 6 mounted on the mounting plate 58 in parallel with the rod 60.
2 are connected with the nut dividing surface penetrating. Further, a gate-shaped housing 64 for restricting the open position is provided above the split nuts 54R and 54L, and the operation rod 62 on the upper side is passed through this, and the cylinder is driven by the housing leg portion when the nuts 54R and 54L are separated. Side nut 54
The other nut 54L is configured to open while supporting the opening operation of R.

In particular, in this mold clamping device, the outer end portions of the split nuts 54R and 54L are inwardly stopper flanges capable of contacting the tip end portions of the tie bars 18 penetrating the movable platen 16 by the mold closing operation. 66R and 66L are provided. The size of the stopper nuts 66R and 66L is set so that the tip surfaces of the tie bars 18 are securely locked to the stopper flanges 66R and 66L even when the split nuts 54R and 54L are opened.
The opening diameter of L is set to be smaller than the end surface diameter of the tie bar 18.

Further, the split nut mechanism 52 is supported by the gate type housing 64 as described above, but in this embodiment, the split nut mechanism 52 as a whole is provided with the tie bar 18.
It is attached to the movable platen 16 so that it can move in parallel to the axial direction of. For this reason, a pair of support shafts 67 projecting and fixed in parallel with the tie bars 18 are provided on the rear surface of the movable platen 16, and the shafts 67 are made to penetrate the gate-shaped housing 64 so that they can be moved back and forth using these as guides. There is. The shaft 67 has a gate-shaped housing 64.
And the movable platen 16 and the shaft 67.
68 and gate type housing 6 provided at the tip of the
The springs 70F and 70R having the seating surface 4 are mounted, and the gate-shaped housing 64 is held at a position where the biasing forces of the springs 70F and 70R are balanced. The strength of the springs 70F and 70R is different before and after the gate-shaped housing 64, and is set so that the biasing force to the movable platen 16 side becomes large. Therefore, the front end surfaces of the split nuts 54R and 54L are elastically biased so as to come into contact with the boss 50 of the ram 42 of the mold clamping cylinder device 38.

A threaded portion 72 that meshes with the split nut mechanism 52 is formed at the end of the tie bar 18 that is inserted into the movable platen 16 side. Further, in FIG. 1, 74 indicates an approach cylinder device for opening and closing the mold.

The operation of the mold clamping device configured as described above is as follows. First, the movable cylinder 1 is driven by driving the approach cylinder device 74 with the split nuts 54R and 54L open.
Fixing plate 1 along the guide of the machine base (not shown)
Move toward 4. On the other hand, the tie bar 18 is the fixed plate 14
The die height adjustment nut 20 provided on the
The length is adjusted so as to project according to the thickness of 0 and 12. The split nuts 54R and 54L are shown in FIG.
As shown in (2), the spring 70R causes the ram 42 to
It is in contact with the boss 50.

Shortly before the molds 10 and 12 are closed, the tip surface of the tie bar 18 has the split nut 5 as shown in FIG.
Stopper flanges 66R, 66 formed on 4R, 54L
Since it contacts L and is prevented from penetrating, split nut mechanism 5
2 separates from the boss 50 of the ram 42. The movement of the split nut mechanism 52 is stopped by the tie bar 18, but the movable platen 16 further moves until the molds 10 and 12 come into contact with each other, and then stops, as shown in FIG. Split nut mechanism 5
Since the closing operation of 2 can be performed while the movable platen 16 is moving, there is no cycle loss.

By supplying pressure oil to the right chamber of the mold clamping cylinder device 38 shown in FIG. 1 after completion of such mold clamping preparation, the ram 42 moves to the left, and the split nuts 54R, 54L are again provided.
And the mold clamping is completed.

On the contrary, in the mold opening step, the pressure oil in the right chamber of the mold clamping cylinder device 38 is lowered, the pressure oil is supplied to the left chamber, and the split nuts 54R, 54L are opened. Nut 5
When the meshing of 4R and 54L is released, the split nut mechanism 52 moves to the right while being in contact with the boss 50 of the ram 42 of the mold clamping cylinder device 38 by the action of the spring 70R having a strong biasing force. Then, the approach cylinder device 74
By supplying pressure oil to the head side of the movable plate 16, the movable platen 16 moves away from the fixed platen 14. The movable platen 16 stops after the set stroke is moved, and the product is extruded by an extruding device (not shown) to complete the molding cycle.

In such an embodiment, the tie bar 18
To adjust the length to match the die height, the die height adjusting nut 20 is rotated. This is realized by driving the chain by a drive motor (not shown) and rotating the sprocket 26 attached to the nut 20. That is, the nut 20 is rotated by the fixed platen 14, and the tie bar 18 screwed onto the fixed platen 14 is moved back and forth to adjust the tie bar length protruding toward the movable platen 16 side. The position where the protruding tip of the tie bar 18 contacts the stopper flanges 66R, 66L of the split nut mechanism 52 is the die height adjustment position. By such adjustment, the length of the tie bar 18 is set, the mold clamping state at the minimum die height is as shown in FIG. 5, and the length by which the tie bar 18 projects to the rear surface side of the fixed platen 14 becomes the maximum. On the contrary, the mold clamping state at the maximum die height is as shown in FIG. 6, and there is no protrusion from the back surface of the fixed platen 14 and the protrusion length to the movable platen 16 side is the maximum. In any case, in the mold clamping state, the tip of the tie bar 18 is held by the split nut mechanism 52 provided on the back surface of the movable platen 16 and does not penetrate therethrough and project to the back surface side. Therefore, the back space of the movable platen 16 can be effectively used.

[0022]

As described above, according to the mold clamping device of the molding machine of the present invention, the die height adjusting nut is attached to the tie bar insertion portion of the fixed plate, and the screw portion screwed to the die height adjusting nut is attached to the outer peripheral surface of the tie bar. A split nut that is engraved and has a mold clamping ram that penetrates the tie bar is attached to the movable plate and that has a stopper flange that abuts the end surface of the tie bar that penetrates the ram and is driven in the radial direction of the tie bar to fix the tie bar. Since it is configured to attach, it is possible to easily adjust the die height, and it is possible to widen the work space on the back of the movable plate without protruding the tie bar from the back of the movable plate during mold clamping. At the same time, it is possible to obtain a compact and space-saving mold clamping device having a structure that can realize miniaturization of the mold clamping device.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold clamping device according to an embodiment in a mold matching state.

FIG. 2 is a cross-sectional view of the mold clamping device immediately before mold clamping.

FIG. 3 is a sectional view showing a tie bar rotation stopping means.

FIG. 4 is a horizontal sectional view and a vertical sectional view of a split nut mechanism.

FIG. 5 is a cross-sectional view of the mold fitting state of the mold clamping device adjusted to the minimum die height.

FIG. 6 is a cross-sectional view of the mold clamping device adjusted to the maximum die height in a mold open state.

[Explanation of symbols]

 10 Fixed Die 12 Movable Die 14 Fixed Plate 16 Movable Plate 18 Tie Bar 20 Die Height Adjusting Nut 22 Screw Part 24 Holding Plate 26 Chain Sprocket 28 Chain 30 Rotation Stopper 32 Tie Bar Insertion Hole 34 Roller 36 Guide Groove 38 Mold Clamping Cylinder Device 40 Cylinder body 42 Ram 44, 46 Pressure oil supply / discharge port 48 Tie bar through hole 50 Boss (ram) 52 Split nut mechanism 54R, 54L Split nut 56 Open / close cylinder 58 Mounting plate 60 Piston rod 62 Operation rod 64 Gate type housing 66R, 66L Stopper Flange 67 Support shaft 68 Spring stopper 70F, 70R Spring 72 Threaded portion 74 Approach cylinder device

Claims (1)

[Claims] 1. A mold clamping device of a molding machine, wherein a fixed plate to which a fixed mold is attached and a movable plate to which a movable mold is attached are connected by a tie bar to perform mold clamping by a mold clamping cylinder device. A die height adjusting nut is attached to the tie bar insertion part of the fixed plate, a screw part to be screwed into this is engraved on the outer peripheral surface of the tie bar, and the movable plate is equipped with a die clamping ram for penetrating the tie bar and the ram is attached. A mold clamping device for a molding machine, comprising a split nut that has a stopper flange that abuts an end surface of a tie bar that penetrates and that is driven in a radial direction of the tie bar and is fixed to the tie bar.