JPS6155856B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vertical mold clamping device used for injection foam molding, compression molding, or the like.

In injection foaming or compression molding methods, in which molten resin is injected and filled into a closed mold, and then the closed position of the mold is changed to expand or compress the molten resin, the closed position of the mold is changed to two stages. A means to do so is needed. As means for changing the closed position, a method is adopted in which the closed position of the movable plate is detected and hydraulically blocked to control the mold position during injection and filling, or the mold position is mechanically controlled. There is.

Among the conventional means described above, when using a hydraulic block, high pressure cannot be applied during injection, and the position of the mold is unstable, making it difficult to perform highly accurate molding.

As for mechanical means, a technology in which a wedge is provided at the joint of the mold to determine the closing position, and control is performed by varying the amount of push of the wedge
6054 (see Japanese Patent Publication No. 56-7860), and a technique in which a plurality of stop cylinders are provided in addition to the mold clamping cylinder to control the closing position of the movable plate, and control is performed using the stop cylinders and rods (see Japanese Patent Publication No. 7860/1986). ).

In the above-mentioned wedge-based control means, the mold structure is more complex than a normal mold because the mold is equipped with a wedge and a cylinder for moving the wedge.
In addition, there were other problems such as lack of versatility.

In addition, control using a stop cylinder and rod requires a stop plate and an electric motor to adjust the position of the rod that passes through the stop cylinder, which not only complicates the structure around the clamping cylinder but also increases the cost. There are drawbacks.

Therefore, we invented a mold clamping device (Japanese Patent Application No. 113306/1982) which eliminates the above-mentioned conventional drawbacks. However, the mold clamping device disclosed therein is of a type that clamps the mold by pressing the mold clamping plate from the back, and a device for controlling the retreating position of the mold clamping plate is installed between the mold clamping cylinder and the mold clamping plate. Therefore, if the mold clamping device is applied as is to a vertical mold clamping device, the mold clamping cylinder will be located at the top, which has the disadvantage of increasing the height of the device and lengthening the hydraulic piping. Moreover, not only does oil leakage treatment and maintenance require a lot of effort, but a new problem arises in that it is structurally difficult to open and close the mold at high speed. The present invention aims to provide a new mold clamping device that is vertical but has a low height and can perform foam molding and compression molding by controlling the retracted position of the mold clamping plate.

The present invention has a plurality of vertical mold clamping cylinders provided on the side of a base plate, a mold clamping piston that protrudes upward from the base plate and also functions as a high-speed opening/closing cylinder, and a penetrating piston inserted into each of the mold clamping pistons. A control mechanism having a tie rod whose lower end is fixed, a fixing plate connected and held to the upper end of the mold clamping piston, a rotating member provided at the center of the fixing plate, and a fixing member installed above the mold clamping plate. and a mold clamping plate retraction position control device.

The present invention will be explained in detail below using illustrated examples.

Reference numeral 1 denotes a base plate, and a plurality of mold clamping cylinders 2, 2 are vertically provided on the side thereof. The mold clamping cylinders 2, 2 are provided with mold clamping pistons 3, 3 of a required length that protrude upward from the base plate 1, and the upper chamber 2a of the mold clamping cylinders 2, 2 is a hydraulically operated prefilter. It is connected to a flow path 5 which is opened and closed by a valve 4.

The mold clamping pistons 3, 3 have a hollow piston rod 3a which also serves as a high-speed opening/closing cylinder, and a tie rod 6, 6 having a longer axis than the mold clamping pistons 3, 3 is inserted through the piston rod 3a. The lower ends of the tie rods 6, 6 are fixed to the mold clamping cylinders 2, 2, and a piston that partitions the interior into two oil chambers 3b, 3c is located inside the mold clamping pistons 3, 3. A head 7 and a plurality of hydraulic passages communicating with the oil chambers are provided.

Further, a mold clamping plate 8 is fitted into the upper end portions of the mold clamping pistons 3, 3, and is integrally connected with clamping members 9, 9. A hydraulic cylinder 10 and a piston 11 are installed inside the center of the mold clamping plate 8, and an upper projecting pin 13 is attached to the lower end of the piston 11 via a plate 12 in a recess.

Reference numeral 14 denotes a fixing plate which is connected and held to the upper ends of the tie rods 6, 6 with nut members 15, 15. At the center of this fixing plate 14, a fixing member 16 of a required length is attached to the center of the upper part of the mold clamping plate 8.
In addition, a mechanism 17 for controlling the retracted position of the mold clamping plate 8
is rotatable and movable up and down.

This control mechanism 17 includes a main body 19 fitted into a mounting hole provided in a fixed plate 14 using a key 18 so as to be movable up and down, a cylindrical rotating member 20 fitted rotatably inside the main body 19, and a seat. It consists of a rotary actuator 22 that is installed on the upper part of the main body 19 via a plate 21 and communicates with a rotating member 20, and is rotatably arranged with a receiving member 23 at the lower edge of the mounting hole of the fixed plate 14. The adjustment ring 24 is held on the fixing plate 14 by fitting with screws provided around the lower part of the main body.

As shown in FIG. 3, protrusions 25 and grooves 26 of the same shape and number are alternately formed on the inner wall of the rotating member 20 and on the circumferential side of the fixed member 16. As shown in FIG.
When these are fitted into each other, the fixed member 16 fits inside the rotating member 20 without contacting the end surface of the rotating member 20, as shown in FIG. 2, and allows the mold clamping plate 8 to retreat upward. do. However, when the rotating member 20 is rotated by the rotary actuator 22 and the position of the convex line 25 is shifted from the concave line 26 as shown in FIG. The rotation member 20 is limited to a position where the end surfaces of the rotary member 20 and the rotary member 20 touch each other, for example, the position shown in FIG.

In the figure, 27 is a mold mounting plate on the base plate, 28 is a mold mounting plate on the lower surface of the mold clamping plate, and 29 is a lower protruding pin at the center of the base plate 1.

Next, the operation will be explained. In the mold closed state shown in FIG. 1, when the prefill valve 4 is opened and pressure oil is supplied to the oil chamber 3b, the mold clamping pistons 3, 3 move upward at high speed. At this time, if the fixed member 16 and rotating member 20 are placed in the position shown in FIG. 3, the mold clamping plate 8 will retreat to the position shown in FIG. Open wide.

Next, when the oil resistance in the oil chamber 3b is removed and pressure oil is supplied to the oil chamber 3c, the mold clamping pistons 3, 3 move forward together with the mold clamping plate 8 toward the base plate 1 at high speed to close the mold. Then, close the prefill valve 4, and close the upper chamber 2a.
At this time, the rotary member 20 is rotated by a required angle by the rotary actuator 22, and the fixed member 16 and the rotary member 20 are
The end surfaces of the protrusions should be in contact with each other. As a result, the mold clamping plate 8 does not retreat to the position shown in FIG. 2, but is supported by the fixing plate 14 via the control mechanism 17, so that it can sufficiently withstand the resin pressure. In the case of injection compression molding, it is sufficient to fill the cavity with molten resin in this state, and then pull the mold clamping plate 8 toward the bed plate using the mold clamping piston, and in the case of injection foam molding, After injection and filling is carried out with the mold clamping plate 8 strongly drawn toward the base plate, the mold clamping plate 8 may be retreated to this state and cooled to the temperature at which it is taken out.

As described above, this invention includes a plurality of vertical mold clamping cylinders 2, 2 provided on the sides of the base plate 1, and
Mold clamping pistons 3, 3 which also serve as high-speed opening/closing cylinders protrude upwards, tie rods 6, 6 which are inserted through each mold clamping piston 3, 3 and fix their lower ends, and upper ends of each mold clamping piston 3, 3. A fixed plate 14 connected and held to the upper end of the tie rod and a control mechanism 17 provided at the center of the fixed plate 14, and a control mechanism 17 provided protruding from the upper part of the clamp plate 8. Since a vertical mold clamping device is constructed from the fixing member 16 and the mold clamping plate retraction position control device, both high-speed opening/closing and mold clamping can be performed using the same mold clamping cylinder and mold clamping piston. Moreover, since the mold clamping cylinder is provided on the side of the base plate, the device can be constructed low. This not only simplifies the arrangement of hydraulic paths, but also simplifies oil leakage treatment and maintenance management, improving work efficiency.

Furthermore, since a device is installed between the mold clamping plate and the fixing member to control the retreating position of the mold clamping plate, it has features such as being able to easily carry out injection foam molding and injection compression molding by manipulating the mold. have

[Brief explanation of the drawing]

The drawings show one embodiment of the vertical mold clamping device according to the present invention, and FIG. 1 is a half longitudinal sectional front view when the mold is clamped, FIG. 2 is a half longitudinal sectional front view when the mold is opened, and FIG. The figure is a cross-sectional plan view of the control mechanism, and FIG. 4 is a cross-sectional plan view of the control mechanism when the rotating member is rotated by 45 degrees. 1... Base board, 2... Mold clamping cylinder, 3... Mold clamping piston, 6... Tie rod, 7... Piston head, 8... Mold clamping plate, 14... Fixing plate, 16...
Fixed member, 17... Control mechanism, 20... Rotating member, 22... Rotary actuator.

Claims (1)

[Claims] 1. A plurality of vertical mold clamping cylinders installed on the side of the base plate, a mold clamping piston that protrudes upward from the base plate and doubles as a high-speed opening/closing cylinder, and a tie rod that penetrates each mold clamping piston and fixes the lower end. and a control mechanism including a mold clamping plate connected to the upper end of each mold clamping piston, a fixed plate connected and held to the upper end of the tie rod, and a rotating member provided at the center of the fixed plate, and the mold clamping plate. 1. A vertical mold clamping device comprising: a fixing member installed on the upper part of the mold clamping plate; and a mold clamping plate retraction position control device.