JP3217838B2 - Mold clamping hydraulic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping hydraulic device for an injection molding machine, and more particularly to a mold clamping device in which a small-diameter actuator for rapid feed is connected to the inside of a hollow piston of a large-diameter actuator for clamping. The present invention relates to a hydraulic device.

[0002]

2. Description of the Related Art In a clamping hydraulic device disclosed in U.S. Pat. No. 4,545,756, a small-diameter actuator is connected to an outer end wall of a large-diameter actuator, and a piston rod of the small-diameter actuator penetrates a piston of the large-diameter actuator. It is connected to the movable support member of the injection molding machine. When the small-diameter actuator presses the movable die against the fixed die, the U-shaped clutch plate supported on the end of the piston of the large-diameter actuator projects to the end face of the piston, and the end flanges of the piston of the large-diameter actuator and the piston rod of the small-diameter actuator And the clamping pressure of the piston of the large diameter actuator is transmitted to the movable mold.

[0003]

However, the above-mentioned mold clamping hydraulic device has a very large overall length because the small-diameter actuator and the large-diameter actuator are connected in series, so that a large floor area is required for installing the injection molding machine. I need.

An object of the present invention is to provide a mold-clamping hydraulic device in which a large-diameter actuator and a small-diameter actuator are combined so as to reduce the overall length, and the installation floor area can be reduced.

[0005]

In order to achieve the above-mentioned object, according to the present invention, a rod is connected to the center of the closed end wall of a cup-shaped hollow piston fitted in a cylinder of a large-diameter actuator for mold clamping. A piston of a small diameter actuator for rapid traverse coupled to a tip of the rod protruding outward from the hollow piston is fitted into a cylinder, and a movable supporting portion is formed at a tip of the cylinder, and a cylinder of the cylinder of the small diameter actuator is formed. A plurality of clutch plates and an actuator for radially projecting / retracting the clutch plates are supported by a flange formed at the base end, and the clutch plates are radially outwardly positioned at a position where the flanges protrude outside the hollow piston. And is configured to abut against the open end wall of the hollow piston.

[0006]

The small-diameter actuator for rapid traverse is disposed inside the hollow piston of the large-diameter actuator for clamping, the piston rod of the small-diameter actuator is connected to the closed end wall of the hollow piston of the large-diameter actuator, and the cylinder of the small-diameter actuator is provided. Is movable. The movable support member is coupled to the distal end of the cylinder of the small-diameter actuator, and the clutch plate is provided on a flange at the base end of the cylinder of the small-diameter actuator.

When the cylinder of the small-diameter actuator protrudes from the inner space of the hollow piston to the outside, the clutch plate protrudes from the flange at the base end of the cylinder. The tightening pressure of the hollow piston is transmitted to the cylinder of the small-diameter actuator via the clutch plate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a mold clamping hydraulic apparatus according to the present invention comprises a large-diameter actuator 10 for clamping, a small-diameter actuator 30 for rapid traverse, and a clutch plate 46 driven by an actuator 40. You. The large-diameter actuator 10 has a seal ring 2 inside the cylinder 12.
A cup-shaped hollow piston 21 fitted with the hollow pistons 21 and 23 is fitted, and a ram 26 integrated with the hollow piston 21 is
And a holding plate 20 which sandwiches a seal ring 18 coupled to the opening end of the holding plate 20. The cylinder 12 is divided into a chamber 16 and a chamber 17 by a hollow piston 21. The open end of the cylinder 12 has a large-diameter portion with an enlarged inner diameter,
9 and a plurality of seal rings 18
It is held by 0. The holding plate 20 is connected to the end wall of the cylinder 12 by a plurality of bolts 11. The chamber 16 has a port 51 and the chamber 17 has a port 52. The port 52 opens to the inner peripheral surface of the cylinder 12 through the internal passage 53 of the cylinder 12, but is normally closed by the peripheral wall of the hollow piston 21. Therefore, the hollow piston 21 is normally suppressed to the operation amount s or less. If the hollow piston 21 exceeds the operation amount s for some reason, the chamber 16 communicates with the port 52 via the internal passage 53 and the hollow piston 21
Colliding with the plate 19 and breaking the seal ring 18 is prevented.

A small diameter actuator 30 couples a rod 28 to the center of the closed end wall 24 of the hollow piston 21. The tip of the rod 28 is connected to a piston 32 on which a seal ring 33 is mounted. The piston 32 is fitted into the cylinder 31 to define a chamber 34 and a chamber 35. Port 54 in chamber 34
However, a port 55 is provided in the chamber 35. The tip of the cylinder 31 has a screw groove 3 for coupling the movable support member 37.
6 is formed. The base end of the cylinder 31 is a flange 38
Are integrally formed, and a plurality of actuators 40 and a clutch plate 46 are provided inside the flange 38. The outer diameter of the flange 38 is slightly smaller than the inner diameter of the opening 27 of the ram 25. A seal ring 39 is attached to a portion where the rod 28 passes through the flange 38.

As shown in FIGS. 2 and 3, each actuator 40 has a piston 42 fitted in a cylinder 41 provided inside a flange 38, and a rod 43 projecting from the piston 42 is connected to a clutch plate 46. . Clutch plate 4
6 is guided and supported by a groove 47 provided in the flange 38. The groove 47 has a projection 47a at the bottom surrounding the cylinder 41. A recess 46a is provided on the inner edge of the clutch plate 46 to avoid interference with the projection 47a when the clutch plate 46 retreats.

Next, the operation of the mold clamping hydraulic device according to the present invention will be described. FIG. 1 shows a state in which the movable mold of the movable mold support member 37 is separated from a fixed mold (not shown), and the molded product is taken out. When pressing the movable mold of the movable mold support member 37 against the fixed mold, first, pressurized oil is supplied from the port 55 of the small-diameter actuator 30 to the chamber 35.
1 is pushed rightward, and the flange 38 projects from the inner space of the hollow piston 21 to the outside through the opening 27. At this time, the oil in the chamber 34 returns from the port 54 to an oil tank (not shown).

As shown in FIG. 4, when pressure oil is supplied to the chamber 45 of the cylinder 41 of the actuator 40,
The clutch plate 46 protrudes radially outward from the outer peripheral surface of the flange 38 due to the rod 2 and the rod 43. At this time, the oil in the chamber 44 returns to the oil tank. Next, the hydraulic pressure in the chamber 35 of the cylinder 31 of the small-diameter actuator 30 is released, and the large-diameter actuator 10 is released.
When the pressure oil is supplied from the port 51 of the cylinder 12 to the chamber 16, the hollow piston 21 is pushed rightward, the end wall 26 of the ram 25 comes into contact with the clutch plate 46, and the cylinder 31 is pushed rightward. The movable die of the movable die supporting member 37 is strongly pressed against the fixed die by the hollow piston 21, and in this state, the molten resin is injected into the inner space of the fixed die and the movable die. At this time, the oil in the chamber 17 returns from the port 52 to an oil tank (not shown).

When returning the movable mold support member 37 after the injection molding, pressurized oil is supplied from the port 52 of the cylinder 12 to the chamber 17, and the hollow piston 21 is returned to the position shown in FIG.
The pressure oil is supplied to the chamber 44 of the cylinder 41 and the clutch plate 46 is supplied.
Into the groove 47 of the flange 38. Pressure oil is supplied from the port 54 of the cylinder 31 to the chamber 34, and the cylinder 31 is retracted into the hollow piston 21.

FIGS. 5 and 6 show a modified embodiment of the clutch plate 46A. The pair of clutch plates 46A are formed integrally with the arm 64 supported on the flange 38 by the pin 65. The clutch plate 46A is fixed to the flange 3 by the actuator 40.
8 is driven to a position protruding radially outward from the outer peripheral surface and a position retracting radially inward. The actuator 40 is mounted on a cylinder 41 whose base end is supported on a flange 38 by a pin 61.
A chamber 44 and a chamber 45 are defined by fitting the piston 42, and a rod 43 projecting from the piston 42 is connected to a clutch plate 46A by a pin 62. The joint 43a at the tip of the rod 43 projects into a triangular groove 63 provided in the clutch plate 46A, and is connected to the clutch plate 46A by a pin 62 passing through the joint 43a. In the embodiment shown, the pin 6
Numeral 2 has large diameters at both ends so that it does not protrude from the plate surface of the clutch plate 46A. The clutch plate 46A and the actuator 40 are connected to the flange 3 similarly to the embodiment shown in FIGS.
It is preferable to dispose it inside the groove provided in 8.

[0015]

As described above, according to the present invention, a rod is connected to the center of the closed end wall of a cup-shaped hollow piston fitted in a cylinder of a large-diameter actuator for mold clamping, and projects outward from the hollow piston. A piston of a small diameter actuator for rapid traverse coupled to a tip of the rod is fitted into a cylinder, a movable supporting portion is formed at a tip of the cylinder, and a plurality of flanges formed at a base end of the cylinder of the small diameter actuator are provided. At the position where the flange projects outside the hollow piston, the clutch plate projects radially outward and the open end of the hollow piston at the position where the flange projects outside the hollow piston. The small-diameter actuator for rapid traverse is arranged inside the hollow piston of the large-diameter actuator for mold clamping. Runode, the overall length as compared with the prior art is greatly shortened, thereby saving floor space of the injection molding machine. In other words, when the flange of the fast-forward piston is housed inside the hollow piston and protrudes outward from the hollow piston during mold clamping, and the clutch plate protrudes radially outward, the piston is opened by the open end wall of the hollow piston. Since it is pushed, the axial dimension of the entire mold clamping device is short, and a long stroke is obtained for the rapid-feed piston. Since the cup-shaped hollow piston is fitted in the cylinder of the large-diameter actuator, the pressure receiving area of the hollow piston is wide, and therefore a large clamping force can be obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a mold clamping hydraulic device according to the present invention.

FIG. 2 is an enlarged side sectional view showing the clutch plate supporting portion.

FIG. 3 is a front sectional view of the same.

FIG. 4 is a side sectional view showing an extended state of the mold clamping hydraulic device.

FIG. 5 is a side sectional view of a clutch plate supporting portion according to a partially modified embodiment of the present invention.

FIG. 6 is a front view of the same.

[Explanation of symbols]

10: Large Diameter Actuator 12: Cylinder 21: Hollow Piston 28: Rod 30: Small Diameter Actuator 31: Cylinder 32: Piston 37: Movable Supporting Member 38: Flange 40: Actuator 46:
Clutch board

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/64-45/68 B29C 33/20-33/28 B22D 17/26

Claims (1)

(57) [Claims] 1. A rod is connected to the center of a closed end wall of a cup-shaped hollow piston fitted in a cylinder of a large diameter actuator for mold clamping, and connected to a tip of the rod protruding outward from the hollow piston. A piston of a small-diameter actuator for rapid traverse is fitted into a cylinder, a movable support portion is formed at the tip of the cylinder, and a plurality of clutch plates and clutch plates are formed on a flange formed at a base end of the cylinder of the small-diameter actuator. An actuator that projects and retracts in the direction of the hollow piston, and at a position where the flange projects outside the hollow piston, the clutch plate projects radially outward to abut against the open end wall of the hollow piston. Mold clamping hydraulic device characterized by the above-mentioned.