JPH0218009A - Controlling device of mold thickness - Google Patents

Abstract

PURPOSE:To easily realize positional control in response to the shifting of a position, which is developed by the change of the mold thickness by a method wherein a screw is provided at the tip of each tie-bar, which is fixed to a movable die plate and each positioning sprocket is axially shifted so as to control the position of each half nut. CONSTITUTION:The engaging position of a screw thread is controlled by controlling the positions of respective half nuts 180 through a chain 195 by means of sprockets 190, on the inner surface of each of which a thread engaging with a screw stock attached on each packing gland 176 is machined. Further, a pulse motor or the like is employed for the rotation of the sprockets 190. The mold thickness at mold close is automatically measured with a linear scale or the like and computed by the number of rotations of the pulse motor so as to operate the amount of the shifting of the engagement of the screw in order to calculate the correction amount and to shift the sprockets to either direction only by the correction amount. Next, each ram 162 is retreated by sending pressure oil to the oil chamber 161B of the ram 162 so as to stop the ram 162 by abutting the ram 162 against the stopper face of the sprocket 190. At this time, the half nut 180 is pushed against the ram 162 by a spring 179 at all times, resulting in completing the controlling of the mold thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mold thickness adjusting device applied to an injection molding machine or the like.

(Prior Art) FIG. 6 shows a conventional mold clamping device, and 60 indicates a support frame. On one end of this support frame 60, a fixed die plate 64 to which a fixed mold 62 is attached is fixed. Further, on the other end of the support frame 60, a movable die plate 68 to which a movable die 66 is attached is slidably mounted so as to face the fixed die plate 64. Further, the fixed die plate 64 includes a plurality of (four in this example) hydraulic cylinders 7.
0, the internal piston 7 of these hydraulic cylinders 70
Tie bars 74 are provided extending in the direction of the movable die plate 68 from the two movable die plate 68 side surfaces.

Further, a boost cylinder 76 is fixed to one side of the fixed die plate 64, and the tip of a rod 80 connected to the internal piston 7B of the boost cylinder 76 is appropriately fixed to one side of the movable die plate 68.

On the other hand, a guide rod 82 having a smaller diameter than the tie bar 74 is provided as a guide member at the tip of the tie bar 74 . For this purpose, each movable die plate 68 is provided with an insertion hole 84 through which the tie bar 74 is inserted, and the movable die plate 68 is provided with an insertion hole 84 approximately relative to the axis of the insertion hole 84 on the side opposite to the surface on which the movable mold 66 is attached. A half nut 86 is provided that moves in the right angle direction. Further, adjacent to the half nut 86, a step portion 88 is formed at the boundary between the guide rod 82 and the tip of the tie bar 74, through which the guide rod 82 is inserted. A stopper 90 capable of locking is provided, and this is appropriately fixed to the movable die plate 68. Further, on the outer periphery of the tip of the tie bar 74, there is a threaded portion 9 that engages with the half naso) 86.
2 is engraved. Further, a connecting member 94 can be coupled to the tip of the guide rod 82, if necessary, for the purpose of synchronizing the movement of each tie bar 74 during a mold clamping operation.

In the mold clamping device in the conventional example configured in this way,
When closing the mold, one oil chamber 96 of the boost cylinder 76
By supplying pressure oil to the movable die plate 68, the movable die plate 68 is moved toward the fixed die plate 64 side. At this time tie bar 7
The guide rod 82 protruding from the tip of the tie bar 4 moves while sliding on the stopper 90, and the tip of the tie bar 74 is smoothly inserted into the insertion hole 84 of the movable die plate 68.

Next, just before the mold closing of the fixed mold 62 and the movable mold 66 is completed, the step 88 formed at the tip of the tie bar 74, that is, at the boundary with the guide rod 82, closes to the stopper 9.
0 (Fig. 7). At this time, the moving die plate 68
By moving the half nut 86 provided on the tie half 86 in a direction substantially perpendicular to the axis of the insertion hole 84 using the moving means 98, it can be brought into engagement with the threaded portion 92 formed on the tie half 4.

As a result, the tie bar 74 can be fixedly coupled to the movable die plate 68. After that, if pressure oil is supplied to one oil chamber 100 of the hydraulic cylinder 70 provided in the fixed die plate 64, the movable die plate 6B is moved to the fixed die plate 64 by directly moving the tie bar 74.
By moving it to the side, the fixed mold 62 and the movable mold 66 can be clamped.

Furthermore, when replacing the mold, in order to adjust the fixed position of the movable die plate 68 relative to the tie bar 74 according to the thickness of the mold, so-called mold thickness adjustment, by changing the operating position of the stopper 90, It can be realized. For example, as shown in FIG. 8, a stopper can be configured as a mold thickness adjusting means. The example shown in FIG. 8 is characterized in that a stopper piece 102 is provided on the guide rod 82 so that it can move forward and backward in a direction substantially perpendicular to the axis of the guide rod 82.

In this case, the stopper piece 102 has a substantially semicircular notch 104 that can come into sliding contact with the guide rod 82.
A pressure cylinder lO whose upper end of 2 is fixed to the support frame 106
It is fixed to the piston rond 11O of No.8.

A plurality of stopper pieces 102 configured as described above are installed on a common support frame 106 at predetermined intervals in the axial direction of the guide rod 82, and this support frame 106 is attached to the movable die plate 68. In this way, multiple stopper pieces 1
02 relative to the guide rod 82, one of the stopper pieces 102 can be moved forward relative to the guide rod 82 by automatic control operation depending on the thickness of the mold, and the tip of the tie bar 74 can be positioned. It is now possible to do it properly.

(Problem to be Solved by the Invention) However, the mold thickness adjusting device shown in FIG. Accordingly, one of the stopper pieces 102 is moved forward relative to the guide rod 82 by an automatic control device to position the tip of the tie bar 74. Therefore, although this method may be sufficient when the mold is changed by a predetermined size, this method alone cannot cope with an arbitrary mold thickness.

Furthermore, if the mold thickness were to vary over a wide range, a large number of stopper pieces would be required.

The present invention has been proposed to solve the above-mentioned conventional problems.

(Means for Solving the Problems) Therefore, the present invention provides a fixed die plate that holds a fixed mold, a movable die plate that holds a movable mold, and a movement of the movable die plate backward relative to the fixed die plate. and a tie bar that is coupled and fixed to the fixed die plate to clamp the mold after the movable die plate approaches the fixed die plate and the fixed mold and the movable mold are closed. The tie bar is fixed to the movable die plate, has a long threaded portion on the opposite side of the fixed end thereof, and has a half nut on the side of the stationary die plate opposite to the die mounting surface that can be opened and closed approximately at right angles to the quiver axis. The meshing position of the half nut is adjusted by rotating the sprocket and using the sprocket itself as a stopper, which is a means to solve the problem.

(Function) A screw is installed at the tip of the tie bar fixed to the movable die plate, and the screw is long enough to engage with the half nut even if the mold thickness changes.The sprocket used to position the half nut is Since the inner surface is threaded, it moves in the axial direction when rotated, allowing the position of the half nut to be adjusted. Furthermore, the position can be easily controlled by automatically controlling the rotation of the sprocket in accordance with the deviation in the meshing position of the tie bar screw and half nut screw caused by a change in mold thickness.

(Example) The present invention will be described in detail below based on the example of the drawings.
The figure shows one embodiment of the device of the present invention, and in the figure, 150 is a base on which a wooden mold clamping device is placed and fixed, and at one end of the base 150 is a fixed die plate 15 on which a fixed mold 152 is attached.
4 is fixed.

The 15th is a moving die plate, and its fixed die plate) 1
A movable mold 156 is attached to the 54 side, and a slide shoe 159 is integrally attached to its leg.
Along the guide rail 151 provided on the base 150,
It is placed so that it can move forward and backward.

The guide portion of the movable guide 58 may be a sliding type guide, a transfer type guide, or may be floated by air or magnetic force.

Furthermore, hydraulic cylinders 160 are formed at the four corners of the fixed die plate 154 to generate mold clamping force after the mold is closed, and oil chambers 161A and 161B are provided inside the hydraulic cylinders 160, sandwiching a ram 162 as described later. It is being As shown in an enlarged view in FIG. 2, the ram 162 has a multi-stage outer periphery with large, medium, and small diameters, and has an insertion hole 1 for a tie bar 164 at its axis.
74 is formed through the mold, and when pressurizing the mold clamp, by sending pressure oil to the one oil chamber 161A, it moves to the right in FIG. 1, brings its tip 163 into contact with the half nut 180, and With the half nut 180 engaged with the tie bar 164, the half nut 180 is further pushed to the right to generate mold clamping force. The tie bar 164 has one end fixed to the movable die plate 15B by a nut 165,
A threaded portion 172 is formed over a predetermined length at the tip of the tie bar 164, and this threaded portion 172 is connected to a half round hole 8 provided on the back side of the fixed die plate 1-154 during mold clamping.
meshes with 0.

Reference numeral 166 denotes a mold opening/closing cylinder attached to the fixed die plate 154 or the movable die plate 158, which moves the movable die plate 58 back and forth.
8 or fixed to the fixed guide eye 54. 175
．． Reference numeral 176 denotes a packing holder which is fixedly installed before and after the portion of the fixed die plate 154 that constitutes the mold clamping cylinder, and the packing holder 176 on the back side of the fixed die plate 154 supports a half lug 180 so as to be movable back and forth. A guide bar 177 is fixed. This guide bar 177
Half nut 18 is made by dividing a nut into two and facing each other.
0 is slidably supported via a bracket 178;
The half nut 180 is always urged by a spring 179 so as to come into pressure contact with the tip 163 of the ram 162. At the same time, the end surface 163a of the ram 162 is also pressed against the stopper surface 190a of the sprocket 190. The half nut 180 can be opened and closed from side to side along a guide bar 181 fixed to the bracket 178 by an opening/closing mechanism (not shown), and is closed and engaged with the threaded portion 172 of the tie bar 164 when the mold is clamped.

In addition, the threaded rod 191 attached to the packing presser 176 has
A sprocket 190 with a thread cut on the inner surface is engaged with the sprocket 190, and the sprocket 190 is moved back and forth in the direction shown by the arrow in FIG. 2 via a chain 195 by a chain drive device such as a stepping motor (not shown). That is, by adjusting the position of the half nand 180, the engagement position of the screw threads can be adjusted.

Next, to explain the operation, when replacing a mold that changes the mold thickness, it is necessary to adjust the mold thickness (screw engagement correction).The operating procedure in this case is as follows. be.

First, turn on the mold thickness setting switch (not shown).

Next, pressure oil is sent to the oil chamber 168A of the mold opening/closing cylinder 166 to bring the molds into close contact (the fixed mold 152 and the movable mold 156
engaged state (Fig. 4). Also sprocket 190
A pulse motor or the like is used to rotate the mold, and the mold thickness when the mold is closed is automatically measured using a linear scale (not shown).
This is rotated by determining the motor rotational speed, and the amount of deviation in screw engagement is calculated by a computer to calculate the correction amount.

Next, pressurized oil is sent to the oil chamber 161A of the ram 162 (low pressure at this time) to move the ram 162 forward, break contact with the stopper surface 190a of the sprocket 190, and rotate in either direction by the amount of correction. (Figure 3).

Next, pressure oil is sent to the oil chamber 161B of the ram 162, and the ram 16
2 and the stopper surface 190 of the sprocket 190
Apply the ram 162 to a and stop it. In this case, since the half nut 80 is always pressed against the ram 162 by the spring 179, the position of the half nut 180 is determined by the position of the sprocket 190, and mold thickness adjustment is completed.

(Effects of the Invention) Since the present invention is configured as explained in detail above,
By cutting the tie bar screw long enough to accommodate the range of mold thickness changes and correcting the slight deviation of the peaks and troughs with the half nut screw, it is possible to mesh at any position. In addition, since the engagement position of the tie bar and half nut is adjusted by rotating the sprocket, there is no variation and it can be done simultaneously. On the other hand, the amount of correction is determined automatically if the mold thickness is known, so it is possible to fully automate the reading of the mold thickness and the movement of the sprocket of the mold thickness adjustment device.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a mold thickness adjusting device showing an embodiment of the present invention, FIG. 2 is a detailed view of the main parts of the mold thickness adjusting device shown in FIG. 1, and FIG. 3 is a main part of the mold thickness adjusting device shown in FIG. Detailed view, FIG. 4 is a front sectional view showing a different operating state from FIG. 1, FIG. 5 is a view taken along arrow C in FIG. 4, and FIG. 6 is a plan sectional view showing an example of a conventional mold clamping device. FIG. 7 is a plan sectional view showing a different operating state from FIG. 6, and FIG. 8 is a side sectional view of the mold thickness adjusting device used in the mold clamping device of FIGS. 6 and 7. Explanation of the main parts of the figure 154--Fixed dive plate 158--Moving dive plate 16t-m-Tie bar 166-Type opening/closing cylinder 172--Threaded part 1so-Half nut 190--Sprocket 191--Threaded rod no. Figure 6 Group 7

Claims (1)

[Claims] a fixed die plate for holding a fixed die; a movable die plate for holding a movable die; means for moving the movable die plate backward relative to the fixed die plate; In a mold clamping device consisting of a fixed die plate and a tie bar that is fixedly connected to the fixed die plate and performs mold clamping after the fixed die and the movable die are closed, the tie bar is fixed to the movable die plate and the tie bar is fixed to the movable die plate. A half nut is provided on the side opposite to the mold mounting surface of the stationary die plate and can be opened and closed at almost right angles to the tie bar axis, and the meshing position of the half nut is adjusted using a sprocket. A mold thickness adjustment device characterized by rotating the sprocket and using the same sprocket itself as a stopper.