JPS63151422A - Straight-hydraulic clamping device for injection molding machine or the like - Google Patents

Abstract

PURPOSE:To provide a straight hydraulic clamping device, compact and economized, by fixing a booster ram of a small diameter, formed to have a large volume of stroke area from the backward position to just before mold clamping and also just after mold clamping to the backward position, to a booster cylinder and also fixing its one end to a moving die plate. CONSTITUTION:When a mold clamping ram 3 moves backward to the left side in the drawing to the extent that the closely contacted faces of both molds (not shown in the drawing), fixed to a fixed die plate (not shown in the drawing, and a moving die plate 9, open slightly, a pipeline 15 connected with a chamber 14 on the piston side of a booster cylinder 6 is opened) and by introducing pressurized oil into a pipeline 17 connected with a R-chamber 16 of the booster cylinder, the moving die plate 9 moves backward to the left side of the drawing at a high speed. As the system is constituted and moved as above-mentioned, the stroke of the clamping ram of a large diameter and heavy weight is reduced to a necessary minimum, and the diameter of a booster ram fixed to the moving die plate moves to a great extent is also reduced, which enabling the moving die plate move up to just before mold clamping and just after mold opening to the backward position travel at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a mold clamping device for a direct pressure type injection molding machine, die casting machine, etc.

(Prior art) The conventionally widely known direct pressure type mold clamping device has pre-filled pulp built into the mold clamping cylinder and requires a large volume of hydraulic oil, and a large diameter and heavy mold clamping ram is required. It was moving at high speed.

(Problems to be solved by the invention) Since the conventional direct pressure type mold clamping device has a built-in pre-filled pulp, the device becomes large in proportion to the mold clamping stroke, resulting in an increase in weight and cost. It was uneconomical. Furthermore, since the large-diameter, heavy-weight mold clamping ram moves over a long stroke, there is always a large amount of hydraulic fluid movement, which makes the hydraulic piping large and complicated, which poses problems in terms of operability and maintenance.

The present invention does not use prefill pulp as in conventional devices, but reduces the stroke of the large diameter and heavy mold clamping ram to a small amount during mold clamping and mold opening, and also reduces the stroke of the small diameter boost ram. The purpose of the present invention is to provide a direct pressure type mold clamping device that is compact and economical by forming a large amount of oil from the retracted position to just before the mold clamping and from immediately after the mold is opened to the retracted position to reduce the amount of oil movement. ○ [Structure of the invention] (Means for solving the problems) In order to achieve the above object, the present invention includes a mold clamping cylinder fixed to the machine base and a large diameter inside the coaxial cylinder. A mold clamping ram whose stroke area is a small amount when the mold is clamped and when the mold is opened, and a boost cylinder is formed at the axial center of the mold clamping ram, and the stroke area of the boost cylinder is set back. To provide a direct pressure type mold clamping device comprising a small diameter boost ram formed in a large amount from a position to just before mold clamping and from immediately after mold opening to a retracted position, and one end of the boost ram is fixed to a movable die plate.

(Function) Since pre-filled pulp is not used, the size can be reduced in the longitudinal direction, and the stroke of the large-diameter, heavy-weight mold clamping ram can be minimized, and the boost ram fixed to the movable die plate can be used. Because the diameter of the die plate has been reduced, it is possible to move the movable die plate forward and backward immediately before mold clamping and immediately after mold opening, which requires less hydraulic oil and reduces the large force required during mold clamping and mold opening. It can act on the tightening ram.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 and 2.

I is a mold clamping cylinder fixed on the frame 2, and a mold clamping ram 3 is fitted into the mold clamping cylinder.

The clamping cylinder has a small diameter in the deep part and a large diameter in the shallow part. The mold clamping ram 3 has a piston ring 4
A large diameter portion having a mounting groove is slidably fitted into the large diameter shallow portion of the mold clamping cylinder 3 so as to be able to stroke slightly in the axial direction by pressure oil acting on the oil chamber 18 and IQ. ing.

The center of the mold clamping ram 3 is a boost cylinder 6, which has a boost ram consisting of a bottomed elongated hole, a piston 7 and a rod 8 that are fitted into the bottomed elongated hole, and the tip of the rod 8 is connected to a movable die. It is fixed to the plate 9 and has oil chambers 14 and 1.
The movable die plate 9 is moved in the axial direction by pressure oil acting on the die plate 6, and moves the movable die plate 9 forward and backward.

A plurality of piston rings 4.5 are installed in the piston ring mounting grooves of the piston 7 of the mold clamping ram 3 and the boost ram, and the R chamber 10 of the mold clamping cylinder and the R chamber of the boost cylinder
In order to prevent the pressure oil in the chamber 16 from leaking to the outside, a sealing material 12 and 13 that can withstand increased pressure is inserted and retained.0 Below, the operation will be explained.0 First, the mold clamping operation will be explained. In response to an operation start signal (not shown), the pipe line 17 leading to the log side chamber 16 of the boost cylinder 6 is opened, and pressure oil is introduced into the pipe line 15 leading to the piston side chamber 14, thereby opening the rod 8. The companion moving die plate 9 fixed at the tip moves forward at high speed to the right in the figure. When the movable die plate 9 moves forward to just before mold clamping, a mold clamping position detection signal (not shown) closes the pipes 15 and 17 leading to the piston side chamber 14 and rod side chamber 16 of the boost cylinder, and at the same time closes the mold. Clamping cylinder 1 of clamping ram 3
<Open the pipe line 11 leading to the chamber 10, and press the F of the mold clamping cylinder.
By introducing pressure oil into the pipe line 19 leading to the chamber 18, the movable die plate moves further to the right, and the large force generated in the large-diameter F chamber 18 of the mold clamping cylinder at the mold clamping position is
The hydraulic pressure in the chamber 14 on the piston side of the boost cylinder 6 is increased to obtain the necessary mold clamping force.

Next, to explain the mold opening operation, in response to a mold opening operation start signal (not shown), the pipe line 15t leading to the piston side chamber 14 of the boost cylinder etc. is opened, and the pressure oil is supplied to the pipe line 17.
and into the R chamber 16 of the boost cylinder. However, the radius of the boost cylinder
Since the chamber 16 has a small diameter, the opening force is small. Therefore, the pipe line 15.17e leading to the piston side chamber 14 and the R chamber 16 of the boost cylinder is kept closed, and the mold clamping cylinder F
When the pipe line 19 leading to the chamber 18 is opened and pressure oil is introduced from the pipe line 11 leading to the R chamber 10 of the mold clamping cylinder, a large opening force is generated and the mold clamping ram 3 retreats to the left in the figure. At the same time, the moving soybean rate 9 also retreats.

Fixed die plate (not shown) and moving die plate 9
When the mold clamping ram 3 has retreated to the left in the figure to the extent that the contact surfaces of both molds (y, not shown) that are fixed to the molds are slightly opened,
When the pipe line 15 leading to the piston side chamber 14 of the boost cylinder 6 is opened and pressure oil is introduced into the pipe line 17 leading to the R chamber 16 of the boost cylinder, the movable die plate 9 retreats to the left in the figure at high speed. .

As it is configured and operates as described above, the stroke of the large-diameter, heavy-weight mold clamping ram is kept to the necessary minimum, and the stroke of the large-diameter, heavy-weight mold clamping ram is fixed to the movable die plate that moves widely. It is possible to increase the speed of the moving die/rate from immediately after mold opening to the retracted position, and it is possible to act on the large workpiece mold clamping ram required during mold clamping and mold opening. In addition, the movement of oil amount can always be kept to a minimum.

Since no prefill valve is used, the length of the device can be reduced, making it more compact and economical.

Since the sliding parts between the mold clamping cylinder and the mold clamping ram and the sliding parts between the boost cylinder and the boost ram are sealed by the sealing members, it is possible to increase the pressure efficiently.

〔Effect of the invention〕

According to the present invention, unlike conventional equipment, prefill pulp is not used, the stroke of the large diameter and heavy mold clamping ram is minimized, and the boost ram, which has a large travel distance, is made small in diameter, thereby reducing the amount of oil. It is possible to always reduce the amount of movement by making it one size and one item.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing a direct pressure type mold clamping device according to an embodiment of the present invention in a retracted position, and FIG. 2 is a partially sectional front view showing a forward position. 1... Mold clamping cylinder, 2... Frame, 3...
Clamping ram, 4... Piston ring, 6... Boost cylinder, 7... Piston, 8... Rod,
9... Moving die rate, 10... R chamber of mold clamping cylinder, +2... Seal material, 14... F chamber of boost cylinder, 16... R9 of boost cylinder, 18... Model F chamber of the tightening cylinder.

Claims (3)

[Claims] (1) A mold clamping cylinder fixed to the machine base, a mold clamping ram having a large diameter coaxially inside and whose stroke area is a small amount when the mold is clamped and when the mold is opened, and the mold A boost cylinder is formed in the axial center of the clamping ram, and a small-diameter boost ram is formed in the boost cylinder with a large stroke area from the retracted position to just before mold clamping and from immediately after mold opening to the retracted position, and one end thereof. A direct pressure mold clamping device for injection molding machines, etc., which is fixed to a moving die plate. (2) A direct pressure type mold clamping device for an injection molding machine or the like according to claim 1, wherein the sliding portions of the mold clamping cylinder and the mold clamping ram are sealed by a sealing member. (3) A direct pressure mold clamping device for an injection molding machine or the like according to claim 1, wherein the sliding portions of the boost cylinder and the boost ram are sealed by a sealing member.