JPH04147809A - Clamping device of molding machine - Google Patents

Abstract

PURPOSE:To make the revolutional movement of a lock ring smooth by allowing the lock ring to be reciprocally revolved through the alternative actuation of two single cylinders, and providing the cylinders in the form of being buried in the wall thickness of a support disc. CONSTITUTION:When a piston 32a is made to advance in supplying hydraulic forces in one cylinder 27a, the piston 32b of another cylinder 27b is pushed by a revolving lock ring 9 and moved rearward. The reciprocal revolution of the lock ring 9 is effected by alternatively supplying hydraulic pressure to cylinders 27a,b, and only pressing forces apply to the connecting part of piston 32a,b and piston rod 35 and the connecting part of the piston rod 35 and lock ring 9. Accordingly, the connecting parts are formed by spherical surfaces with which are in contact. On the peripheral surface of the lock ring 9, a receiving seat 29 is formed, and in the cylinder holes 30 provided on a support disc 3 in the tangential direction of the lock ring 9, a cylinder tubes 31 are inserted, and piston rods 35 having the connecting parts as spherical joints and pistons 32a,b are successively inserted therein, thereby fabricating cylinders 27a,b.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention relates to a mechanical lock type mold clamping device used in injection molding machines, etc., in which a movable platen moved to a mold clamping position by a mold opening/closing cylinder is connected to a locking ring. This invention relates to a lock ring drive structure in a mechanical lock type mold clamping device that rotates and fixes the lock ring.

(Prior Art) An example of a mechanical lock type mold clamping device having a structure in which a movable platen is fixed by rotating a lock ring is shown in FIGS. 3 to 6. In the figure, 1 is a fixed plate, 2 is a movable plate, 3 is a support plate that supports the mold clamping reaction force applied to the movable plate 2, 4 is a tie bar, 5 is a mold thickness adjustment device, and 6 is fixed to the back of the movable plate 2. 7 is a mold opening/closing cylinder fixed to the center of both sides of the support plate, 8 is a mold clamping rod integrated with the piston of the mold clamping cylinder 6, and 9 is rotatably attached to the support plate 3. lock ring,
10 is a lock cylinder that rotates the lock ring 9;
1 is the fixed side mold fixed to the fixed platen 1, 12 is the movable platen 2
The movable mold is fixed to the

A screw 13 is cut at the end of the tie bar 4 on the side of the support plate 3, and a nut 15 provided on a die thickness adjustment gear 14 is screwed into the screw 13. The mold thickness adjustment gear 14 of each tie bar meshes with a large diameter synchronous gear 16 provided at the center of the support plate, and this synchronous gear is rotationally driven by a mold thickness adjustment motor 17 via a drive gear 18. These members form a mold thickness adjustment device 5, and by rotating a mold thickness adjustment motor 17, the distance between the fixed platen 1 and the movable platen 2 is adjusted according to the dimensions of the molds 11 and 12.

The mold clamping rod 8 and the lock ring 9 have spline teeth that slide with a gap between each other when the mold is opened and engage with each other when the mold is clamped, and there is a hollow hole in the center of the support plate 3 through which the mold clamping rod 8 can pass. A hole 21 is provided. Third
As shown in the figure, when the clamping loft 8 and the spline teeth of the lock ring 9 are in phase, the clamping rod 8 can pass into the hollow hole 21 of the support plate (Figure 5), and As shown in the figure, when the spline teeth of the mold clamping rod 8 and the lock ring 9 are out of phase, the mold clamping loft 8 is prevented from retreating as shown in FIG. 6 by the contact of both spline teeth. This rotational movement of the lock ring is performed by the lock cylinder 10. The lock cylinder 10 is a double-acting cylinder whose head end is pivotally supported by a bracket 22 fixed to the support plate 3, and whose tip end is pivoted to the tip of an arm 23 fixed to the lock ring 9. 24 is a holding plate, and 25 is a support plate, which is fixed to the support plate 3 and is in sliding contact with the side surface of the lock ring 9. The support plate 25 also has the function of preventing the tip of the mold clamping rod 8 from momentarily sinking when the direction of the pressure oil in the mold clamping cylinder 6 is switched at the start of mold clamping.

The operation of the mold clamping device is performed in the following steps. Hydraulic pressure is supplied to the head end side of the mold opening/closing cylinder 7 and the long end side of the mold clamping cylinder 6, and the movable platen 2 moves forward to close the fixed mold 1.
After detecting with a limit switch or the like that the mating surfaces of 1 and the movable mold 12 are closed, the lock cylinder 10 is operated to shift the phase of the spline teeth of the lock ring 9 as shown in FIG. Hydraulic pressure is supplied to the head end side of the mold clamping cylinder 6. The hydraulic pressure applied to the piston surface of the mold clamping cylinder 6 is transmitted to the tie bar 4 via the mold clamping loft 8, the lock ring 9, and the support plate 3, and is firmly connected between the fixed mold 11 and the movable mold 12. A large mold clamping force is generated.

When opening the mold, hydraulic pressure is supplied to the long end side of the mold clamping cylinder 6 to close the tip of the mold clamping rod 8 and the lock ring 9.
Open a slight gap between the two and turn the lock song 9 with the lock cylinder 10 to bring the phases into alignment as shown in Fig. 3. Next, supply hydraulic pressure to the roto Y end side of the mold opening/closing cylinder 7. to open the movable platen 2 toward the support plate 3 side.

(Problems to be Solved by the Invention) In the device having the structure described above, the lock cylinder IO and its hydraulic piping are attached to the surface of the support plate 3 on the movable plate side. However, since the tie bar 4 and the mold opening/closing cylinder 7 are attached around this part, workability when performing piping etc. is poor, and the position where the rotational force acts on the lock song 9 from the lock cylinder 1o and the resistance against it are poor. The disadvantage is that there is a shift in the position where the

In addition, adjustment work is required to align the spline teeth of the support plate 3 and lock ring 9 to the state shown in Fig. 3.
This adjustment work must be performed by, for example, screwing the end fitting 26 onto the rond end of the lock cylinder 10 and adjusting its position. However, such adjustment work is extremely difficult because the lock cylinder 10 is located in a position surrounded by the tie bar 4, the mold opening/closing cylinder 7, and the safety cover provided outside the mold clamping device. There is even a risk of personal injury when moving the movable platen to check its operation.

(Means for Solving the Problems) In this invention, the rotation of the lock ring 90 is
The rotation is made by two single-acting cylinders 27a and 27b arranged in opposite directions in the tangential direction of Everything is resolved.

As shown in the illustrated embodiment, the structure in which the cylinders 27a and 27b are built-in is a structure in which the cylinder hole 30 is provided directly in the support plate 3, or a structure in which a commercially available cylinder is inserted into a hole provided in the support plate. It is also possible to do this.

(Operation) The cylinders 27a and 27b rotate the lock ring 9 only by the movement of pushing the lock ring 9 in the circumferential direction via the piston rod 35. Hydraulic pressure is supplied only to the head end side of the two cylinders 27a and 27b, and when hydraulic pressure is supplied to one cylinder 27a and its piston 32a moves forward, the piston 32b of the other cylinder 27b moves in the - direction. It is pushed back by the lock ring 9 which is pushed by the piston 32a and rotated. The reciprocating rotation of the lock ring 9 is performed by alternately supplying hydraulic pressure to the two cylinders 27a and 27b, and when the lock ring 9 rotates in either direction, the pistons 32a and 32b and the piston rod 35 Only a pressing force acts on the connecting portion between the piston rod 35 and the lock ring 9.

Therefore, as shown in the embodiment, these connecting parts can be formed by convex and convex spherical surfaces that abut each other, and as shown in the illustrated embodiment, a seat 29 is formed on the circumferential surface of the lock ring 9 to provide support. Insert the cylinder tube 31 into the cylinder hole 30 provided in the plate 3 in the tangential direction of the lock ring 9,
By sequentially inserting the piston rod 35 whose connecting portion is a spherical joint and the pistons 32a and 32b, the cylinder 2
7a and b can be assembled.

Further, in the above structure, the stroke of one cylinder 27a is restricted by the piston 32b of the other cylinder 27b reaching its head end. Therefore, the positions of both rotation ends of the lock ring 9 can be adjusted by making the head end members 39 of the cylinders 27a, 27b so that their positions can be adjusted in the axial direction of the cylinders using screws or the like.

When using commercially available cylinders as the cylinders 27a and 27b, the head end of the cylinder is pivoted to a placket fixed to the side of the support plate with a pin parallel to the rotation center axis of the lock ring, and the height of the bracket is adjusted. This allows the positions of both rotation ends of the lock ring 9 to be adjusted.

(Embodiment) FIGS. 1 and 2 show an embodiment of the present invention. The lock ring 9 is provided with notches 28 facing upward from the support plate on both sides in the diametrical direction of the center of its thickness, and the bottom surfaces 29a and 29b thereof are processed into concave spherical surfaces. The support plate 3 is provided with a cylinder hole 30 facing the bottom surfaces 29a and 29b of the notch, and a cylinder tube 31 is fitted into this cylinder hole. The cylinder tube 31 is supported by a stepped portion of the cylinder hole 30 so as to be fixed within the support plate 3, and is also held down by a head flange 36, which will be described later. The piston 32a%b fitted into the cylinder tube 31 has a cushion protrusion 33 on the end surface on the head end side, and the end surface 34 on the Rond end side is a concave curved surface with the same radius as the bottom surface 29 of the lock ring notch. . The piston rods 35a and 35b have both ends formed into convex curved surfaces having a curvature equal to the curvature of the bottom surface 29 of the notch and the curvature of the rod end side end surface 34 of the piston, and the lock ring 9
It is simply sandwiched between the notch bottom surface 29 and the pistons 32a and 32b. The head flange 36 has a screw hole in the center and is fixed to the upper surface of the support plate with bolts or the like. A head end member 3 whose tip is hermetically inserted into the cylinder tube 31 is inserted into the screw hole of the head flange.
9 are screwed together, and a flow path 40 for hydraulic oil is provided in the center of this head end member. The head end member 39 moves forward and backward in the axial direction of the cylinder by rotating, thereby adjusting the upward movement position of the pistons 32a, b of each cylinder. 41 is a lock nut for fixing the set position of the head end member.

Fig. 1 shows the state when the phases of the spline teeth of the lock ring 9 and the mold clamping loft 8 are matched with each other. Pressure oil is supplied to the lock cylinder 37a on the left side of the figure, and the cylinder on the right side of the figure The piston 32b of the head end member 3
It is in contact with 9.

Therefore, by rotating the head end member 39 on the right side of the figure, the angle of the lock ring 9 at this time can be finely adjusted. Fig. 2 shows the state when the spline teeth of the lock ring 9 and the mold clamping rod 8 are out of phase with each other. Pressure oil is supplied to the lock cylinder 27b on the right side of the figure, and the lock cylinder on the opposite side is supplied with pressure oil. Piston 32a abuts its head end member 39.

(Effects of the Invention) According to the structure of the present invention described above, the line of action of the lock cylinder and the center of the rotation resistance acting on the lock ring can be made to coincide, so that the rotation operation of the lock ring can be made smoother. become. Further, since there is no need to provide any member for rotating the lock ring on the movable plate side of the support plate, the distance between the support plate and the movable plate can be reduced accordingly, and the device can be made smaller. Furthermore, assembling the cylinder for rotating the lock ring and piping the hydraulic piping to the cylinder can be done in an open space, greatly improving work efficiency, and also adjusting the rotation position of the lock ring. This makes adjustment extremely easy, and there is no danger in performing adjustment operations while moving the movable platen.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a support plate showing an embodiment of the present invention, with FIG. 1 showing the unlocked state and FIG. 2 showing the locked state. Figures 3 to 6 show a conventional mold clamping device. Figure 3 is a front view of the support plate showing the unlocked state, Figure 4 is the front view of the support plate showing the locked state, and Figure 5 is the same as the one shown in Figure 3. A cross-sectional view taken along line A-A of FIG. 6, B, C, D of FIG.
It is an E sectional view. In the figure: Movable plate: Support plate: Mold opening/closing cylinder 9: Lock ring 27a, b Niji cylinder

Claims (1)

[Claims] (1) It has a movable plate (2) and a support plate (3), and has a movable plate (
2) is opened and closed by a mold opening/closing cylinder (7) interposed between it and the support plate (3), and when the mold is clamped, the piston of the mold clamping cylinder (6) is inserted into the lock ring (9) built into the support plate (3). )
In a mold clamping device of a molding machine having a structure in which a lock ring (9) is rotated and locked, two single-acting cylinders (27a, 27a,
A mold clamping device for a molding machine, characterized in that the cylinders (27a, b) are embedded in the thickness of a support plate (3) and are reciprocally rotated by the alternating operations of (b). (2) The connecting portions between both ends of the piston rod (35) of the cylinder (27a, b), the piston (32a, b) and the lock ring (9) form a contact pair that makes surface contact with each other, and the contact surface 2. The mold clamping device according to claim 1, wherein the mold clamping device has a spherical surface. (3) A head end member (39) whose position is adjustable in the longitudinal direction of the cylinder is provided at the head end side end of the cylinder (27a, b), and the position of this head end member can be adjusted. by lock ring (9)
3. The mold clamping device according to claim 1, wherein the mold clamping device adjusts the angles of both rotation ends of the mold clamping device.