JPH018332Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a mold release device for a synthetic resin molding machine.

Conventional mold release devices for synthetic resin molding machines are used for mold clamping,
When the movable platen is moved backward during mold opening by the cylinder that opens the mold, a connecting plate provided at the rear of the fixed platen moves forward in conjunction with the movable platen, and the mold attached to the fixed platen moves forward. The proximal end of the release pin, which is provided so that the tip can move in and out of the mold, is moved forward against the elastic force of the return spring to cause the tip of the release pin to protrude into the mold, thereby forming the mold inside the mold. Normally, products are designed to be released from the mold, but when it is required to increase the molding speed, the mold clamping and mold opening speeds of the movable platen are increased, so the mold release pin connected to the movable platen is The ejection speed must also be high, which has the disadvantage that a strong impact is applied to the molded product, often causing damage to the molded product.

The present invention was completed with the aim of providing a mold release device for a synthetic resin molding machine that does not have the above-mentioned drawbacks, and will be described in detail below using a foamed synthetic resin molding machine as shown in the drawings as an example.

Reference numerals 1 and 1' denote fixed mold mounting plates and fixed plates that are provided facing each other at a required interval on the base 3, and a plurality of cylinders are installed on both sides of one fixed mold mounting plate 1. 4 is arranged facing backward, and the mold 2 is attached to the front, and the plurality of tie bars 5 stretched between the fixed mold mounting plate 1 and the fixed plate 1' are provided with one mold mounting plate. A movable mold mounting board 6 facing the board 1 is fitted so as to be able to move forward and backward, and a mold 7 that is paired with the mold 2 is mounted on the front surface of the movable mold mounting board 6. A cylinder 8 facing each cylinder 4 is disposed on both sides of the movable mold mounting plate 6, and each cylinder 8 has a piston rod 10 fitted into the cylinder 4.
A piston rod 9 whose stroke can be freely adjusted is inserted so that its tip contacts the tip of the piston rod 9 to form a constant gap between the joint surfaces 2' and 7' of both the molds 2 and 7. As shown in FIG. 2, the cylinder 4 disposed on the fixed mold mounting board 1 includes a piston 11 fixed to the proximal end of the piston rod 10 and a piston rod 12 that operates when the molded product is released from the mold. An annular spacer 14 is provided between the two pistons 11 and 13, and a lid that closes off the spacer 14 and one end of the cylinder 4. The body 15 has a port 16 for supplying and discharging fluid,
17 is formed, and the ports 16 and 17 are connected to a fluid supply pipe 18 via a directional switching valve 19, and a lid body 20 that closes the other end of the cylinder 4 is provided with an appropriate number of ports. A ventilation hole 21 is transparently provided. On the other hand, the piston rod 9 fitted into the cylinder 8 disposed on the movable mold mounting board 6 has a head as shown in FIG. 3 at one end facing the fixed mold mounting board 1. A finely adjustable threaded rod 28 having a diameter of 22' is screwed into the rod, and an adjustment screw 28 for adjusting the stroke is screwed into the other end.
A lid body 23 and a flanged lid body 24 which close both ends of the cylinder 8 and into which the piston rod 9 is inserted are provided with ports 25 and 26 for fluid supply and discharge, respectively. It is connected to a fluid supply pipe 18 via a switching valve 27 . The distal ends of the piston rods 12 are connected by a connecting plate 29, which is fitted and supported by a plurality of guide rods 30. Furthermore, a plurality of mold release pins 31 are slidably attached to the back surface of the mold 2 and whose tips are pushed into the mold 2 by being pressed by the connecting plate 29 that moves forward by the operation of the cylinder 4. The pin 31 is normally pulled toward the connecting plate 29 by the elastic force of a return spring 32 enclosed around its outer periphery. In addition, 33 is a stop curler with a set screw that is inserted into the piston rod 12 in order to set the operating amount of the piston rod 12 and adjust the advancing position of the mold release pin 31, 34 is a raw material supply device, and 35 is the tip of the piston rod 36. This is a cylinder attached to the stationary plate 1' to move the movable mold mounting plate 6 fixed to the stationary plate 1' forward and backward.

With this configuration, the directional control valve 19
Pressure fluid is supplied from the directional control valve 27 into the cylinder 4 through the port 16 to bring the piston rod 10, which brings one side of the piston 11 into close contact with the lid body 20, into the forward state.
5 into the cylinder 8, and as shown in FIG. The piston rod 9 has one end surface of the adjusting screw 28 whose position has been adjusted in close contact with the flanged lid body 24.
By operating the cylinder 35 while the cylinder 35 remains in the retracted state, the movable mold mounting plate 6 is moved to the fixed mold mounting plate 1 side, and the tip of the piston rod 10 of the cylinder 4 and the tip of the piston rod 9 of the cylinder 8 are connected. When the head 22' comes into contact with the cylinder 3
5 is stopped to stop the movement of the movable mold mounting plate 6 to maintain a certain gap required when filling raw material beads between the joint surfaces 2' and 7' of the molds 2 and 7. Then, the material supply device 34 fills the space between the molds 2 and 7 with raw material beads, and then the directional control valve 19 is switched to stop the supply of pressure fluid from the port 16 to stop the pressure on the piston rod 10. After releasing the pressure, actuate the cylinder 35 again to move the movable mold mounting plate 6 forward toward the fixed mold mounting plate 1, and the unpressurized piston rod 10 will be pushed by the piston rod 9. Since the molds 2 and 7 are moved backward, the joint surfaces 2' and 7' of the molds 2 and 7 come into contact with each other. Next, a pressure booster (not shown) is activated to clamp and press the molds 2 and 7 together, and then steam is sent into the molds 2 and 7 using a conventional method to foam the raw material beads. , 7, a predetermined foamed synthetic resin product is molded therein. After the molding is completed in this way, the operation of the cylinder 35 is stopped, the pressure bond between the joint surfaces 2' and 7' of the molds 2 and 7 is released, and pressure fluid is applied to the ports 16 and 26 to release the piston rods 10 and 9. is advanced to form, for example, a larger gap than the above between the joint surfaces 2' and 7' of the molds 2 and 7, and the molded product attached to the mold 2 is floated, and then the fixed mold mounting plate is moved forward. Compressed air is instantaneously ejected into the mold 2 on the first side from an ejection port (not shown), and then the movable mold mounting plate 6 is moved back in the opposite direction by the operation of the cylinder 35 to open the mold, and the pressure fluid is released. When this is supplied to the port 17, the mold release piston rod 12, which was being advanced by the pressure fluid from the port 16, stops the connecting plate 29 and moves backward until the collar 33 comes into contact with the lid 15, so that the mold release is performed. The connecting plate 29, which is movable toward and away from the base end of the pin 31, allows the tip of the release pin 31, which faces the inside of the mold 2 so as to be freely retractable, to protrude into the inside of the mold 2 against the elastic force of the return spring 32. Become, therefore,
The molded product in the mold 2 is projected out of the mold and released from the mold, and thereafter the same operations as described above are repeated to perform foam molding.

As is clear from the description of the above embodiments, the present invention includes a plurality of cylinders arranged rearward in the mold mounting board, and a connecting plate that is moved forward by the cylinders to move the release pin by the elastic force of the return spring. Since the tip of the release pin is made to protrude into the mold by moving it forward against the movement of the mold, the release pin does not interlock with the movable mold mounting board, and is connected to the movable mold mounting board. If the molding cycle is shortened by increasing the mold clamping and mold opening speeds, the ejection speed of the molded product will increase and there is no risk of damaging the molded product, and the product yield can be increased.
It has extremely great practical value as it eliminates the drawbacks of conventional mold release devices for synthetic resin molding machines.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view showing an embodiment of the present invention, Figure 2 is a partially cutaway front view of a cylinder installed on a fixed mold mounting board, and Figure 3 is a movable mold mounting board. FIG. 1... Mold mounting board, 2... Mold, 4... Cylinder, 12... Piston rod, 29... Connection plate,
31...Release pin, 32...Return spring.

Claims (1)

[Scope of utility model registration request] A plurality of cylinders 4 are arranged rearward on a mold mounting board 1 with a mold 2 mounted on the front side, and the tips of the piston rods 12 of the cylinders 4 are connected with a connecting plate 29. A release pin 31 is attached to the back surface of the mold 2, the tip of which is pressed by the connecting plate 29 which advances due to the operation of the cylinder 4 and projects into the mold 2 against the elastic force of the return spring 32. Mold release device for synthetic resin molding machines.