JP2003154566A - Mold clamping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold clamping device having a novel structure capable of being compactly realized as a whole inclusive of an oil pressure pump for supplying and discharging operation oil while ensuring sufficiently large mold clamping force by a hydraulic cylinder mechanism for mold clamping. SOLUTION: A booster cylinder 104 is supported on a device base 10 directly or indirectly through a fixing plate 12 or the like and a pair of booster pistons 108 and 108 are fitted in the booster cylinder 104 on both sides in the axial direction thereof in a slidable manner. Eccentric plate cams 126 and cam driving motors 138 for pressing and driving the respective booster pistons 108 from the outside are provided to drive the booster pistons 108 through the cam driving motors 138 and the eccentric plate cams 126. By this constitution, the oil pressure generated in the booster cylinder 104 is guided to the mold clamping hydraulic cylinder mechanism 28 to perform mold clamping operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device used in an injection molding machine for synthetic resin materials or the like, and particularly to a mold clamping hydraulic cylinder mechanism for mold clamping in addition to a mold opening / closing drive mechanism for high-speed mold opening / closing. The present invention relates to a mold clamping device provided.

[0002]

2. Description of the Related Art Conventionally, a mold clamping device in an injection molding machine has a fixed platen and a movable platen arranged opposite to each other on a device base, and the movable platen can be moved to a fixed platen to which a fixed mold is attached. By moving a movable plate with a movable mold attached thereto in the approaching / separating direction, the mold opening / closing operation and the mold clamping operation are performed.

Further, in such a mold clamping device, it is necessary to secure a sufficiently large mold clamping force and to speed up the mold opening / closing operation in order to improve the molding cycle. In particular, as a medium to large-sized mold clamping device, an electric or hydraulic mold opening / closing drive mechanism for opening / closing a link mechanism such as a toggle or a crank, a ball screw mechanism, or a small diameter hydraulic cylinder mechanism is used. Separately, it has been proposed that a mold clamping hydraulic cylinder mechanism for clamping is applied between a movable platen and a fixed platen to perform a mold clamping operation.

However, in the conventional mold clamping device provided with such a mold clamping hydraulic cylinder mechanism, a hydraulic pump for supplying and discharging hydraulic oil to the mold clamping hydraulic cylinder mechanism is separate from the main body of the mold clamping device. Installed in the mold clamping hydraulic cylinder mechanism, it is unavoidable that the mold clamping device, including the hydraulic circuit, becomes large in size. However, there is a problem that it is long and complicated.

A hydraulic pump for supplying / discharging hydraulic fluid to / from the mold clamping hydraulic cylinder mechanism may be fixedly mounted on the mold clamping device body such as the device base, a fixed platen or a movable platen. In order to secure a sufficient amount of hydraulic fluid to be supplied to and discharged from a mold clamping hydraulic cylinder mechanism that has a large piston area in order to obtain a large mold clamping force, a plunger-type hydraulic pump that has been generally adopted in the past has been used. However, it is inevitable that such a large hydraulic pump is directly supported by the equipment base, or indirectly supported by the equipment base via a fixed plate or the like. It was not realistic to equip the.

[0006]

The present invention has been made in view of the circumstances as described above, and the problem to be solved is that a hydraulic cylinder mechanism for mold clamping secures a sufficiently large mold clamping force. At the same time, it is an object of the present invention to provide a mold clamping device having a novel structure that can be realized compactly as a whole including a hydraulic pump that supplies and discharges hydraulic oil.

[0007]

Aspects of the present invention made to solve such problems will be described below. The constituent elements used in each of the following aspects can be used in any combination as much as possible. Further, the aspects and technical features of the present invention are not limited to those described below, but are described in the entire specification and the drawings, or the invention idea that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on this.

According to a first aspect of the present invention, a fixed platen and a movable platen are arranged to face each other on a device base, and the movable platen is movable in the approaching / separating direction with respect to the fixed platen so that the movable platen is movable. A mold opening / closing drive mechanism for performing a high-speed mold opening / closing operation is provided for the fixed platen, and the movable platen and the fixed platen are closed under a mold closed state in which the movable platen is positioned close to the fixed platen by the mold opening / closing drive mechanism. In a mold clamping device provided with a mold clamping hydraulic cylinder mechanism that exerts a mold clamping force between them to perform a mold clamping operation, in both axial directions of a boosting cylinder supported directly by the device base or indirectly through a fixed plate or the like. A pressure-increasing cylinder mechanism is constructed by slidably fitting a pair of pressure-increasing pistons to the above, and a pair of eccentric plate cams and cam drive motors for pressing the pair of pressure-increasing pistons from the outside are provided. Then, the cam driving motor drives the pair of pressure boosting pistons through the pair of eccentric plate cams to guide the hydraulic pressure generated in the pressure boosting cylinder mechanism to the mold clamping hydraulic cylinder mechanism. The feature is that the tightening operation is performed.

In the mold clamping device having the structure according to this embodiment, the double piston type pressure increasing cylinder in which the pair of pressure increasing pistons are fitted from both sides in the axial direction and the pressure increasing piston are pressed and driven from the outside. By adopting a pair of eccentric plate cams, each of the booster pistons can obtain a large effective piston area as a whole even if the diameter of each booster piston is reduced. It is possible to generate a large hydraulic pressure in the cylinder chamber while suppressing the driving force required for the. Moreover, by adopting the double piston type pressure boosting cylinder, even if the stroke of each pressure boosting piston is reduced, a large effective piston stroke can be obtained as a whole by both pressure boosting strokes. It is possible to obtain a large supply / discharge amount of hydraulic oil in the pressure boosting cylinder while suppressing the stroke required for one pressure boosting piston.

Therefore, a pressure boosting cylinder mechanism capable of generating a large hydraulic pressure can be realized with a simple structure in which the strength required for a drive system such as an eccentric plate cam for driving each pressure boosting piston is suppressed. At the same time, the diameter and stroke of each pressure boosting piston and the outer diameter of the eccentric plate cam that drives the pressure boosting piston are both small, and the compact size makes it possible to obtain a large hydraulic oil supply / discharge amount. The cylinder mechanism and its drive system can be advantageously realized.

Therefore, in the mold clamping device having the structure according to the present embodiment, the pressure and the pressure required for the mold clamping hydraulic cylinder mechanism in which a large piston area is set in order to obtain a large mold clamping force are provided. Since the booster cylinder mechanism that constitutes the hydraulic pump capable of satisfying the displacement can be realized compactly with a simple structure, the fixed installation of the hydraulic pump on the mold clamping device body can be advantageously realized. As a result, a mold clamping device that can exert a sufficiently large mold clamping force can be realized compactly as a whole, including a booster cylinder mechanism as a hydraulic pump that supplies and discharges hydraulic oil to and from the mold clamping hydraulic cylinder mechanism. It becomes.

In this aspect, for example, a servo motor can be preferably used as the cam driving motor, and the eccentric plate cam is driven via a gear mechanism or the like. As the mold opening / closing drive mechanism, any of various known devices that can exert a mold opening / closing drive force on the movable plate can be adopted. For example, a small diameter hydraulic cylinder mechanism or a ball screw mechanism is used. Any of an electric drive mechanism or a link drive mechanism in which a driving force of a hydraulic cylinder or an electric motor is applied to a movable plate by using a link mechanism such as a crank mechanism or a toggle mechanism can be adopted.

Further, in this aspect, the mold clamping hydraulic cylinder mechanism (1) directly exerts a mold clamping force between the movable platen and the fixed platen, and (2) on the opposite side of the fixed platen sandwiching the movable platen. Alternatively, the mold clamping force may be indirectly applied between the movable platen and the fixed platen by arranging the pressure platen on the plate and driving the movable plate relative to the pressure platen. Here, in the former (1), as described in, for example, Japanese Patent Application Laid-Open No. 2-72909, Japanese Patent Application Laid-Open No. 3-202325, and Japanese Patent Application Laid-Open No. 9-24520, a hydraulic cylinder mechanism for mold clamping is used. While the structure in which the fixed plate or the movable plate is supported is preferably adopted, in the latter (2), for example, Japanese Patent Laid-Open No.
As described in Japanese Patent Laid-Open No. 1-188122, Japanese Utility Model Laid-Open No. 3-55213, Japanese Unexamined Patent Publication No. 6-8289, etc., a configuration in which a mold clamping hydraulic cylinder mechanism is supported on a pressure receiving plate or a movable plate is preferable. Will be adopted.

A second aspect of the present invention is characterized in that, in the mold clamping apparatus according to the first aspect, an interlocking mechanism for interlocking and rotating the pair of eccentric plate cams is provided. To do. In the mold clamping device having the structure according to the present embodiment, the interlocking mechanism enables the rotational driving force to be transmitted to the pair of eccentric plate cams by a simple mechanism and the operation of the pressure boosting cylinder mechanism. Stability can be improved. As the interlocking mechanism, for example, a transmission gear mechanism that transmits the rotation of the output shaft of the cam driving motor to the pair of eccentric plate cams at the same deceleration rate (gear ratio) can be preferably used.

According to a third aspect of the present invention, in the mold clamping device according to the second aspect, a plurality of the pressure boosting cylinders in which the pair of pressure boosting pistons are slidably fitted are provided, and each of them is provided. The plurality of eccentric plate cams that exert a driving force on each pair of pressure boosting pistons slidably fitted in the pressure boosting cylinder are interlocked with each other by the interlocking mechanism to be rotationally driven. And In the mold clamping device having the structure according to the present mode as described above, by providing a plurality of pressure boosting cylinders, even if the diameter or stroke of each pressure boosting piston is reduced, the plurality of pressure boosting pistons are effective as a whole. It is possible to obtain the piston area and effective piston stroke,
Therefore, it is possible to supply a larger amount of pressure oil to the mold clamping hydraulic cylinder mechanism with a sufficient amount of oil while further advantageously suppressing the driving force and stroke required for each one pressure boosting piston. is there.

A fourth aspect of the present invention is the mold clamping device according to any one of the first to third aspects, wherein a coil spring is accommodated in the pressure boosting cylinder, and the pressure boosting cylinder is accommodated. It is characterized in that the biasing force of the coil spring is always applied in a direction in which the pair of pressure boosting pistons slidably fitted are separated from each other. In the mold clamping device having the structure according to the present mode, the contact pressure of the booster piston with respect to the eccentric plate cam is largely secured based on the biasing force of the coil spring,
Since the contact state between the pressure boosting piston and the eccentric plate cam is always maintained stably, the stability of the driving force transmission operation of the eccentric plate cam to the pressure boosting piston can be further advantageously improved.

According to a fifth aspect of the present invention, in the mold clamping device according to any one of the first to fourth aspects, a retracting type cylinder mechanism is adopted as the mold clamping hydraulic cylinder mechanism, By selectively acting the hydraulic pressure generated by the pressure cylinder mechanism on a plurality of cylinder chambers provided in the mold clamping hydraulic cylinder mechanism, the mold clamping hydraulic cylinder mechanism causes the movable platen to approach / separate from the fixed platen. It is characterized in that it is driven in both directions to perform the mold clamping operation and the strong mold opening operation. In the mold clamping device having the structure according to the present mode as described above, a large driving force generated by the pressure increasing cylinder mechanism, and by extension, the mold clamping hydraulic cylinder mechanism, is exerted not only in the mold clamping operation but also in the strong mold opening operation after molding. As a result, both the high-pressure mold clamping operation and the strong mold opening operation can be advantageously realized by one hydraulic cylinder mechanism.

A sixth aspect of the present invention is the mold clamping apparatus according to any one of the first to fifth aspects, in which the fixed position is opposed to the fixed plate on the apparatus base by a predetermined distance. And a plurality of tie bars extending in parallel to each other across the fixed plate and the pressure receiving plate, and the movable plate is fixed to the fixed plate by the tie bars. While guiding the movement between the pressure plates,
The mold clamping hydraulic cylinder mechanism is provided on the pressure receiving plate, and the pressure increasing cylinder is provided so as to extend between two tie bars adjacent to each other in the circumferential direction of the pressure receiving plate, and the pressure increasing cylinder is opened toward the two tie bars. The pressure boosting cylinder mechanism is configured by fitting the pair of pressure boosting pistons into the openings on both sides in the axial direction of the pressure boosting cylinder, and the pair of eccentric plates that exert a driving force on the pair of pressure boosting pistons. It is characterized in that the cams are rotatably supported by using the two tie bars. In this aspect, in the mold clamping device including the pressure receiving plate, both the mold clamping hydraulic cylinder mechanism and the pressure boosting cylinder mechanism can be favorably supported by the pressure receiving plate, and the pressure receiving plate and the fixed platen are also provided. The eccentric plate cam is supported by making good use of the tie bar, which is a strength member that is laid between the eccentric plate and the movable plate to support the eccentric plate cam, thus simplifying the support structure of the eccentric plate cam and reducing the number of parts. The booster cylinder mechanism can be made more compact.

Further, a seventh aspect of the present invention is the mold clamping device according to the sixth aspect, further comprising a reinforcing member for mutually connecting and reinforcing the tie bars supporting the pair of eccentric plate cams. The eccentric plate cam is arranged between the reinforcing member and the pressure receiving plate in the tie bar. In the mold clamping device having the structure according to the present mode, the drive reaction force of the pressure boosting cylinder mechanism that acts on the eccentric plate cam by reinforcing the tie bar and by extension the supporting shaft of the eccentric plate cam by the reinforcing member. With respect to the above, the strength against can be advantageously secured with a simple structure, and the operation of the eccentric plate cam and thus the operation of the pressure boosting piston can be further stabilized.

An eighth aspect of the present invention is the mold clamping apparatus according to the sixth or seventh aspect, wherein the mold clamping piston of the mold clamping hydraulic cylinder mechanism provided on the pressure receiving plate is mounted on the movable plate. A connecting means for connecting / disconnecting the movable board is provided so that the movable board is moved by the mold opening / closing drive mechanism in a state where the engagement by the connecting means is released to disengage the movable board from the pressure receiving board. A high-speed mold opening / closing operation is performed, while a driving force from the mold clamping hydraulic cylinder mechanism is applied to the movable plate via the connecting means while the movable plate is engaged with the pressure receiving plate by the connecting means. What I did to make it work
Characterize. In the mold clamping device having the structure according to the present mode as described above, when the mold opening / closing operation is performed, the mold opening / closing drive mechanism is driven independently from the mold clamping hydraulic cylinder mechanism at a high speed with a small driving force to save energy and speed. Various mold opening / closing operations can be realized. The connecting means employed in this aspect is, for example, a mechanical ram that is fixed to the movable plate on the mold clamping center axis and projects toward the pressure receiving plate, and a plurality of mechanical rams are provided in a region over a predetermined length of the mechanical ram. While providing the engaging concavity and convexity, the mold clamping piston is provided with a locking member that is immovable in the mold opening / closing direction, and the locking member is appropriately engaged / unlocked with any engaging irregularity or hole of the mechanical ram. By being detachable, it can be advantageously constructed.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings in order to more specifically clarify the present invention.

First, FIGS. 1 to 7 show a mold clamping device as an embodiment of the present invention. That is, the intermediate position during the mold opening / closing operation in the mold clamping device of the present embodiment is shown in FIG.
And the maximum mold open position is shown in FIG. 2 and the minimum mold closed position is shown in FIG. Also, FIG.
4 is an enlarged view of the vertical section in the maximum mold open position shown in FIG.
5 and an enlarged view of the plane in the minimum mold closed position shown in FIG. 3 is shown in FIG. Furthermore,
6 to 7 are cross-sectional views of such a mold clamping device, taken along the lines VI-VI and VII-VII in FIG.

As shown in these figures, the mold clamping device of this embodiment comprises a stationary platen 12 and a pressure receiving plate 14 which are fixedly supported by the device base 10 and are spaced apart from each other and face each other. ing. Further, four tie bars 16 are arranged in parallel to each other across the fixed platen 12 and the pressure receiving plate 14, and the movable platen 18 is fixed by being guided by these tie bars 16. 12 and pressure plate 14
Are arranged so as to be movable between the facing surfaces. The mold clamping device is combined with an appropriate injection device to form an injection molding machine, and at the time of injection molding, a fixed mold 20 mounted on the fixed plate 12 and a movable mold 22 mounted on the movable plate 18. It is designed to open, close and close the mold. Since the basic structure of such a mold clamping device is a well-known part, detailed description thereof will be omitted.

Here, in the mold clamping device of this embodiment, the pressure receiving plate 14 and the movable platen 18 are connected to each other by a link mechanism 24 as a mold opening / closing drive mechanism, and the link mechanism 24 opens and closes the mold. The driving force is exerted on the movable platen 18 by being driven by the motor 26 for high speed die opening / closing operation. Further, the pressure receiving plate 14 is provided with a main cylinder mechanism 28 as a mold clamping hydraulic cylinder mechanism, and a main ram 30 as a mold clamping piston provided in the main cylinder mechanism 28 is provided with a movable plate 1.
By being connected to the mechanical ram 32 that is fixedly installed on the movable plate 8 by the connecting mechanism 34 as a connecting means, a large driving force by the main cylinder mechanism 28 is exerted on the movable plate 18 to perform the mold clamping operation and the strong mold opening. It is designed to operate. The structures of the link mechanism 24, the main cylinder mechanism 28, the mechanical ram 32, the coupling mechanism 34, and the like for realizing the mold opening / closing operation, the mold clamping operation, and the strong mold opening operation will be described in detail below.

More specifically, the above-mentioned link mechanism 24 for connecting the pressure receiving plate 14 and the movable plate 18 to perform a high speed mold opening / closing operation.
Is a support board 36 disposed between the opposing surfaces of the pressure receiving board 14 and the movable board 18, a first connecting link 38 connecting the support board 36 to the pressure receiving board 14, and the support board 36 to the movable board 18. It is configured to include a second connecting link 40 to be connected.

The support board 36 has a rectangular frame shape as a whole, and the tie bars 16 are slidably inserted into the four corners of the support board 36 so that the support board 36 can move with the pressure receiving board 14 while being guided by the tie bars 16. It is supported so as to be capable of reciprocating at a predetermined interval between the facing surfaces of the board 18. In addition, the support board 36,
The connecting rods 42 are assembled by penetrating the respective central portions of the wall portions on the left and right sides facing each other. This connecting rod 4
2 extends horizontally so as to be orthogonal to the mold clamping center axis 44 of the mold clamping device extending in the mold opening and closing direction, and
Connecting rod 42 which is projected outward from the support board 36
A right-side turning plate 46a and a left-side turning plate 46b as a pair of right-left turning members are attached to both axial ends of the above so as not to rotate relative to each other. As shown in FIG. 7, the right rotating plate 46a is composed of a gear having gear teeth on its outer peripheral surface.

A mold opening / closing motor 26 including a servomotor is mounted and fixed on the upper wall of the support board 36. The rotational driving force of the mold opening / closing motor 26 is transferred to a gear box 48. It is adapted to be transmitted to the right rotary plate 46a via the transmission gears 50 and 52. In the present embodiment, the pair of rotating plates 46a and 46b are integrally reciprocally rotated about the central axis of the connecting rod 42 within a range of less than half a circumference by the mold opening / closing motor 26. There is.

Further, the pair of rotating plates 46a, 46b are provided with first connecting pins 54a, 54b projecting at corresponding positions around the connecting rod 42, and the pair of rotating plates 46a, 46b. Second connection pins 56a and 56b are provided on the opposite sides in the radial direction of the first connection pins 54a and 54b sandwiching the connection rod 42 in FIG. And
The first connecting link 38a on the right side and the first connecting link 38 on the left side with respect to the first connecting pins 54a, 54b on the rotating plate 46a on the right side and the rotating plate 46b on the left side, respectively.
b is rotatably locked at one end in each longitudinal direction. In addition, the right rotation plate 46a and the left rotation plate 46
For each second connecting pin 56a, 56b in b,
The second connecting link 40a on the right side and the second connecting link 40b on the left side are rotatably locked at one end in each longitudinal direction.

Further, the pair of rotating plates 46a, 46b.
Right and left pair of first connecting links 38a, 38 locked to
The other end portion in the longitudinal direction of b is a pair of right and left connecting pins 5 projecting substantially in the center in the height direction on both right and left side surfaces of the pressure receiving plate 14.
8a and 58b are rotatably locked. On the other hand, the other ends in the longitudinal direction of the pair of second connecting links 40a, 40b locked to the pair of rotating plates 46a, 46b project substantially in the center in the height direction of the right and left side surfaces of the movable plate 18. A pair of right and left connecting pins 60a, 60b provided
, Respectively, are rotatably locked.

As a result, the pressure receiving plate 14 and the movable plate 18 are
On both right and left sides (front side and back side of the mold clamping device in FIG. 1), the rotating plates 46a and 46b and the first connecting link 38 are provided.
a, 38b and second connecting links 40a, 40b are connected to each other by a link mechanism 24. Then, the pressure receiving plate 1 fixed to the device base 10
4, while the movable plate 18 and the support plate 36 are supported so as to be freely displaceable in the approaching / separating direction, the pair of right and left rotating plates 46a, 46b are integrally formed as a mold opening / closing motor. By being driven to rotate by 26, a driving force in the approaching / separating direction is exerted between the pressure receiving plate 14 and the movable plate 18 via the link mechanism 24.
The high-speed mold opening / closing operation is performed within a stroke range in which the link mechanism 24 between the maximum mold opening position shown in FIG. 2 and the minimum mold closing position shown in FIG. ing. The first and second connection links 3 on the right and left
8a, 38b and 40a, 40b are substantially arcs curved so as to be convex upward and downward in order to avoid interference with the connecting rod 42 and mutual interference between the connecting links at the maximum mold open position. In addition to being shaped, in order to give each connecting link great rigidity, it has a two-plate structure in which plate members of substantially the same shape are stacked in the plate thickness direction and fixed to each other.

Further, the pressure receiving plate 14 has a hollow block shape having a central hole extending in the direction of the mold clamping center axis 44, and the main cylinder 62 is formed in the pressure receiving plate 14 by utilizing this central hole. And the main cylinder 62
A main cylinder mechanism 28 as a backward movement type cylinder mechanism (mold clamping hydraulic cylinder mechanism) that constitutes the mold clamping drive means and the mold opening drive means by the main ram 30 penetrating through and slidably fitted thereto. Are formed. That is, the main cylinder mechanism 28 is
An annular mold clamping cylinder chamber 66 that extends in the circumferential direction between the outer peripheral surface of the main ram 30 and the inner peripheral surface of the main cylinder 62 on both axial sides of the piston portion 64 of the main ram 30 fitted in the two. And powerful type opening cylinder chamber 6
Eight.

On the other hand, the movable platen 18 is fixedly provided with a mechanical ram 32 projecting toward the pressure receiving plate 14 on the mold clamping center shaft 44. The mechanical ram 32 has a solid or hollow large-diameter rod shape, and one end in the axial direction is fixed to the central portion of the movable platen 18, while the other end in the axial direction is supported. It penetrates through the board 36, extends to the pressure receiving board 14, and is inserted into the central hole of the main ram 30 in a loosely inserted state with a gap. Further, an insertion hole 70, through which the connecting rod 42 inserted and supported by the support plate 36 is inserted, is formed in the axially intermediate portion of the mechanical ram 32 so as to penetrate in the horizontal direction. In order to allow the displacement of the support board 36 between the 18 portions, the insertion hole 70 is formed over a predetermined length in the axial direction of the mechanical ram 32. A protective cover 72 is fixed to the axially outer end of the main ram 30 to cover the mechanical ram 32 inserted into the main ram 30.

On the outer peripheral surface of the mechanical ram 32,
A plurality of convex peaks 74 and concave troughs 76 linearly extending in the axial direction (4 in this embodiment) are formed. Furthermore, a locking ring 78 is externally attached to the mechanical ram 32. Although described in detail later, the locking ring 78 has a substantially continuous annular shape or a substantially cylindrical shape that is continuous in the circumferential direction, and is connected to the movable plate 18 from the main ram 30 assembled to the pressure receiving plate 14. By being housed in the cylindrical housing 80 protruding toward the outside, the axial end surface and the outer peripheral surface are constrained, and relative displacement with respect to the main ram 30 in the axial direction and the radial direction is prevented, and the mold clamping center shaft 44 is mounted. It is held rotatably in the circumferential direction. The inner peripheral surface of the locking ring 78 is exposed from the cylindrical housing 80, and is directly opposed to the outer peripheral surface of the mechanical ram 32 inserted. Then, with respect to the inner peripheral surface of the locking ring 78, a plurality of mountain portions 74 formed on the outer peripheral surface of the mechanical ram 32.
A plurality of concave valleys 82 and convex peaks 84 corresponding to the valleys 76 are formed so as to extend over the entire length in the axial direction. The mechanical ram 32
Each of the peaks 74 is a large diameter portion having a substantially constant outer diameter dimension, and each trough portion 76 is a small diameter portion having a substantially constant outer diameter dimension. .
On the other hand, each trough portion 82 of the locking ring 78 is a large diameter portion having a substantially constant inner diameter dimension, and each crest portion 84 is a small diameter portion having a substantially constant inner diameter dimension. It is said that.

Thus, as shown in FIG. 8, the peaks 74 of the mechanical ram 32 enter the valleys 82 of the locking ring 78 and the valleys 7 of the mechanical ram 32.
By mechanically aligning the mechanical ram 32 and the locking ring 78 with each other in the circumferential direction so that the peaks 84 of the locking ring 78 are inserted into the mechanical ram 32,
Without being locked by the locking ring 78, the mechanical ram 32 and thus the movable plate 18 can be freely displaced in the axial direction relative to the locking ring 78 and then the main ram 30.

Further, each mountain portion 74 of the mechanical ram 32
In addition, each crest portion 84 of the locking ring 78 is grooved in the circumferential direction, so that the saw-teeth-shaped meshing teeth 86 and 88 are arranged in the axial direction at a predetermined pitch. Has been formed. In addition, each mountain portion 7 of the mechanical ram 32
In each of the plurality of meshing teeth 86 formed in 4, the base side (movable plate 18 side) of the mechanical ram 32 is an inclined surface, and the protruding tip side of the mechanical ram 32 is substantially aligned with the mold clamping center shaft 44. It is a vertical plane that intersects at right angles. On the other hand, a plurality of meshing teeth 88 formed on each mountain portion 84 of the locking ring 78.
In each case, the main ram 30 side is an inclined surface, and the movable platen 18 side is a vertical surface that is substantially orthogonal to the mold clamping center axis 44.

Then, the locking ring 78 is rotationally driven in the circumferential direction from the non-locking state of the mechanical ram 32 and the locking ring 78 (see FIG. 8), whereby the mechanical ram 32 and the locking ring 78 are moved. The meshing teeth 86, 88 enter the circumferential direction so as to mesh with each other in the serrated projections and recesses, so that the peaks 74, 84 of the mechanical ram 32 and the locking ring 78 are positioned. They will be aligned and engaged in the axial direction. This allows
The mechanical ram 32 and the locking ring 78 are prevented from relative displacement in the axial direction, and the mechanical ram 32 is locked by the locking ring 7.
8, the main ram 30 is coupled and fixed to the main ram 30 in the axial direction, and as is clear from this, in the present embodiment, the mechanical ram 32 and the locking ring 78 are used to interlock each other. A coupling mechanism 34 as a coupling means that can be engaged / disengaged with is configured. Further, since the meshing teeth 86 of the mechanical ram 32 are formed in large numbers at a predetermined pitch over a region of a predetermined length in the axial direction,
At a plurality of positions in the mold opening / closing direction of the mechanical ram 32, the locking ring 78 supported by the main ram 30 can be locked / disengaged from the mechanical ram 32.
As a result, the mechanical ram 32 can be engaged with the main ram 30 by the connecting mechanism 34 including the locking ring 78 at various mold closing completion positions that differ depending on the size of the mounted mold. It is like this.

The meshing teeth 86 of the mechanical ram 32 and the meshing teeth 88 of the locking ring 78 are adapted to mesh with each other between the inclined surfaces and between the vertical surfaces, and particularly, in the protruding direction of the main ram 30. When a driving force (rightward in FIG. 4) is applied to the mechanical ram 32 to drive the movable platen 18 in the mold clamping direction, the meshing teeth 86 of the mechanical ram 32.
The vertical surfaces of the meshing teeth 88 of the locking ring 78 are pressed against each other to transmit the force. In addition, in the present embodiment, the locking ring 78 is provided at least in the circumferential direction in the mountain portion 8.
An engagement / disengagement hydraulic cylinder mechanism 90 for reciprocally rotating by 4 and the valley portion 82 in the circumferential direction is fixedly supported and assembled to the main ram 30. Then, the protruding tip portion of the rod of the engagement / disengagement hydraulic cylinder mechanism 90 is engaged with the rotating piece 92 fixed to the engagement ring 78, whereby the driving force of the engagement / disengagement hydraulic cylinder mechanism 90 is increased. The locking ring 78 is exerted as a rotational driving force. The rotating piece 92 is provided with a locking ring 78.
From the hydraulic cylinder mechanism 90 for engagement and disengagement with respect to the elongated hole extending in the radial direction of the locking ring 78.
The protruding tip of the rod is slidably locked. Furthermore, although it is not necessarily clear from the drawings and is not described in detail here because it is a well-known technique, the movable platen 18 has an ejector mechanism for releasing the molded product after molding when molding the resin product, and the ejector mechanism. The ejector drive motor 94 for driving the mechanism is provided.

Further, in the present invention, the pair of pressure increasing cylinder mechanisms 96, 96 are integrally provided in the mold clamping device. The pressure boosting cylinder mechanism 96 is directly or indirectly supported on the apparatus base via a fixed plate or the like (including a fixed plate, a movable plate, and a pressure receiving plate), and particularly in this embodiment, the pressure receiving plate 14 is used. It is provided in. The pressure oil generated by driving these pressure boosting cylinder mechanisms 96, 96 utilizes a hydraulic circuit as exemplarily shown in FIG. 4 to control valves 98, 100, 102.
By switching control of the mold, the main cylinder mechanism 28, which is the mold clamping hydraulic cylinder mechanism, is driven by being selectively supplied to the mold clamping cylinder chamber 66 and the strong mold opening cylinder chamber 68. Has become.

As shown in the enlarged view of FIG. 9, these pressure boosting cylinder mechanisms 96, 96 are formed so as to project rearward (opposite to the movable platen 18) at both upper and lower ends of the pressure platen 14. Each of the pressure increasing cylinders 1 and 2 is provided with a cylindrical pressure increasing cylinder 104, 104 as a pressure increasing cylinder.
04 and 104 are arranged so as to extend in a substantially horizontal direction across a pair of tie bars 16 and 16 that are horizontally opposed to each other on both upper and lower sides.
Further, in each pressure boosting cylinder 104, openings 106, 1 on both sides in the axial direction, which are opened toward each tie bar 16, are provided.
From 06, a pair of pressure boosting pistons 108, 108 are slidably fitted. Such pressure boosting pistons 108, 10
8 has a block shape corresponding to the opening 106 of the pressure boosting cylinder 104, and an outer peripheral surface provided with a well-known oil seal (not shown) is axially opposed to the inner peripheral surface of the pressure boosting cylinder 104. In the displaceably press-contacted state, the pressure-increasing cylinder 104 is fitted and supported through the openings 106, 106, respectively.
Both opening portions 106, 106 are closed, and a cylinder chamber 110 is formed between the pressure boosting pistons 108, 108 in the pressure boosting cylinder 104. Further, the pressure boosting cylinder 10 is provided at the opening ends on both sides in the axial direction of the pressure boosting cylinder 104.
An annular stopper lid 112 for preventing the pressure boosting piston 108 from coming out of the opening 4 (opening 106) is fixed. The cylinder wall of the pressure boosting cylinder 104 has an opening in the axial center as shown in FIG. 4 and is connected to a mold clamping hydraulic cylinder mechanism via an external hydraulic pipe.
Is provided.

Further, the pressure boosting piston 108 is opened at the axially inner end surface facing the cylinder chamber 110, and the recessed portion 1 is formed.
14 is formed, and the cylinder chamber 110
The compression coil spring 118 is accommodated and arranged in each of the two ends of the compression coil spring 118.
The booster piston 108 is fitted into each recess 114 and positioned and held. As a result, both booster pistons 10
A biasing force in the separating direction is constantly exerted between 8 and 108. The boosting pistons 108, 108 are
By the biasing force of the compression coil spring 118 being applied, under the condition that no external force is exerted,
The stopper lid 112 is elastically held at the axially outward moving end by the contact with the stopper lid 112.

A pair of support pieces 116 having a flat plate shape are integrally provided on the axially outer end surface of the pressure boosting piston 108 so as to project outward in the axial direction. A cam follower 120, which is a known follower roller, is inserted between the pair of support pieces 116, 116, and the cam follower 120 serves as the pair of support pieces 1.
16 and 116 are laid across and are rotatably supported on a pivot 122 extending in a direction substantially orthogonal to the axial direction of the pressure boosting piston 108.

On the other hand, the movable board 1 is penetrated through the pressure receiving board 14.
The tip portions of the four tie bars 16 extending to the side opposite to 8 are connecting frame bodies 124 as reinforcing members having a substantially rectangular frame shape.
Are connected and fixed to each other. Further, an eccentric plate cam 126 for externally pressing and driving the pair of pressure boosting pistons 108, 108 is externally attached to each tie bar 16 located between the connecting frame body 124 and the pressure receiving plate 14. A pair of eccentric plate cams 126 is provided for each of the pair of pressure boosting pistons 108, 108. The eccentric plate cam 126 has an eccentric plate shape in which the radial dimension is changed in the circumferential direction around the central axis,
A substantially circular hole-shaped insertion hole 128 formed in a substantially central portion thereof
A tie bar 16 is inserted through the tie bar 16 and is rotatably disposed and supported by the tie bar 16 via a sliding member such as a bearing, and the outer peripheral cam surface of the eccentric plate cam 126 is in contact with the cam follower 120. .

Further, drive gears 130 are fixed to a total of four eccentric plate cams 126 externally mounted on each tie bar 16. The drive gear 130 is integrally provided with a small-diameter cylindrical connecting cylinder portion 132 extending in the axial direction,
By being externally attached to the tie bar 16, the tie bar 16 is supported rotatably around the central axis through a sliding member such as a bearing. Further, the eccentric plate cams 126 are externally inserted into the connecting cylinder portions 132 of the drive gear 130, respectively, and the eccentric plate cams 126 and the connecting cylinder portions 13 are also inserted.
Reference numeral 2 denotes a key groove and a key member that are key-fitted to each other and are connected to each other in the circumferential direction such that they cannot be displaced relative to each other. As a result, the eccentric plate cam 126 and the drive gear 130 are integrally rotated around the tie bar 16. Further, while each drive gear 130 is constituted by an external gear, as shown in FIG. 6 etc., all four drive gears 130 rotate on the mold clamping center shaft 44. The large-diameter interlocking drive gear 136, which is movably supported between the pressure receiving plate 14 and the connection frame body 124, meshes with each other. And the interlocking drive gear 136
Is driven via transmission gears 140 and 142 by a pump motor 138 which is fixed to the lower part of the pressure receiving plate 14 and is composed of a servo motor or the like as a cam driving motor.

As a result, in this embodiment, the interlocking drive gear 136 is driven by the pump motor 138 to drive the four drive gears 130 in conjunction with each other, so that the pair of tie bars are provided on both upper and lower sides of the pressure receiving plate 14. The eccentric plate cams 126 mounted on the 16 are driven to rotate, and the eccentric plate cams 1 are driven by the urging force of the compression coil springs 118.
Both pressure boosting pistons 108, 108, which are constantly in pressure contact with 26 via a cam follower 120,
According to the rotation of 126, they are driven in the axial direction in association with each other in the approaching / separating direction. The pair of pressure boosting pistons 108, 108 are driven in a direction in which they approach each other, so that pressure oil can be generated in the cylinder chamber 110 of the pressure boosting cylinder 104. Particularly, in the present embodiment, each pair of pressure boosting cylinder mechanisms 96 mounted on the tie bar 16 between the pressure receiving plate 14 and the connecting frame body 124,
A total of four pressure boosting pistons 96, 96, are driven in an interlocking manner by the interlocking drive gear 136, the four drive gears 130, etc., and thus the pair of cylinder chambers 110, 1
A large amount of pressure oil generated as a whole is rapidly applied to the mold clamping cylinder chamber 66 and the strong mold opening cylinder chamber 68 of the main cylinder mechanism 28, which is the mold clamping hydraulic cylinder mechanism, through the hydraulic pipe. It has become
A sufficient amount of oil is secured.

As is apparent from this, in the present embodiment, the eccentric plate cams 126, 126 exerting a driving force on the pair of pressure boosting pistons 108, 108 are interlocked with each other so as to be rotationally driven. The mechanism is configured to include an interlocking drive gear 130, a drive gear 136, and the like. Further, in the present embodiment, a plurality of cylinder chambers provided in the main cylinder mechanism 28 as the backward movement type cylinder mechanism is configured to include the mold clamping cylinder chamber 66 and the strong mold opening cylinder chamber 68.

Next, the mold clamping operation at the time of injection molding in the mold clamping device having the above structure will be described.

That is, in order to start injection molding from the mold open state as shown in FIGS.
The fixed mold 20 is mounted on the movable platen 18 and the movable mold 22 is mounted on the movable platen 18 to perform high-speed mold closing operation. In such a high-speed mold closing operation, first, the locking ring 78 is unlocked with respect to the mechanical ram 32 as shown in FIGS. 4 and 8 (the meshing teeth 86 of the mechanical ram 32 and the locking ring 78).
By holding the meshing teeth 88 of the mechanical ram 32 in a state where they are not meshed with each other)
8 can be freely displaced with respect to the main ram 30.
With the movable plate 18 and the pressure receiving plate 14 separated, the link mechanism 24 is driven by rotating the right and left rotary plates 46a and 46b by the mold opening / closing motor 26 attached to the support plate 36. At least, such rotating plate 4
The turning power of 6a and 46b is applied to the first and second connecting links 38.
By applying between the pressure receiving plate 14 and the movable platen 18 via a, 38b and 40a, 40b, the movable platen 18 is displaced by the mold closing, and the intermediate platen as shown in FIG. The movable platen 18 is drivingly displaced to the mold closing position as shown. This completes the high speed mold closing operation.

As is apparent from FIG. 2 showing the mold open state and FIG. 3 showing the mold close completed state, the link mechanism 24 has the first and second connecting links 38a, 38b and 40a, 40b, respectively. It can be operated from the mold open state to the mold close complete state within a stroke range where it does not reach the most contracted state and the most fully extended state. This allows
After completion of the mold closing, the link mechanism 2 accompanying the mold clamping operation as described later
4 is allowed to be passively actuated in the extending direction.

Then, after completion of the high-speed mold closing operation, the mold clamping operation at high pressure is started. When performing the mold clamping operation, as shown in FIG.
Under the completion state of the high-speed mold closing operation as shown in FIG. 2, the power supply to the mold opening / closing motor 26 for driving the link mechanism 24 is stopped, or the mold opening / closing motor 2 is operated by a clutch or the like.
The transmission of the driving force from 6 to the link mechanism 24 is blocked, and the first and second connecting links 38 of the link mechanism 24 are blocked.
The driving force is not transmitted to a, 38b and 40a, 40b, and there is no load. Then, the locking ring 78 mounted on the main ram 30 constituting the main cylinder mechanism 28 of the pressure receiving plate 14 is rotationally driven by the engagement / disengagement hydraulic cylinder mechanism 90, and the locking ring 78 is engaged with the mechanical ram 32. The mechanical ram 32 and thus the movable platen 18 are fixed to the main ram 30 by keeping the locked state (the state where the meshing teeth 86 of the mechanical ram 32 and the meshing tooth 88 of the locking ring 78 mesh with each other). The movable platen 18 is fixed relative to the movable platen 18 so that the movable platen 18 can be displaced integrally with the main ram 30. When the movable platen 18 and the pressure receiving plate 14 are engaged with each other, each tie bar 1 is driven by the pump motor 138 mounted on the pressure receiving plate 14.
6 rotatably drive the eccentric plate cam 126 attached to 6,
Each pressure boosting piston 108 of the pressure boosting cylinder mechanism 96, 96,
108 is slidably driven, and the generated hydraulic pressure is guided to the mold clamping cylinder chamber 66 of the main cylinder mechanism 28. As a result, the driving force exerted on the main ram 30 in the projecting direction is exerted between the pressure receiving plate 14 and the movable plate 18 via the locking ring 78 and the mechanical ram 32, whereby the movable plate 18 and the fixed plate 1 are
A large mold clamping force is applied between the two to clamp the movable mold 22 and the fixed mold 20.

Further, under such a mold clamping condition, the fixed mold 20 is
The molten resin material is injected and filled into the molding cavity formed between the movable mold 22 and the movable mold 22, and after cooling and solidifying, the strong mold opening operation is performed. In such a strong mold opening operation, the mold of the main cylinder mechanism 28 is held with the link mechanism 24 held in a free state under the completion of the mold clamping operation and the cooling and solidification of the molten resin material as shown in FIG. After the supply of the pressure oil to the tightening cylinder chamber 66 is stopped and the hydraulic pressure is released, the control valve 100 of the hydraulic circuit is switched, and the pressure oil generated by the pressure boosting cylinder mechanisms 96, 96 is generated as described above. , Leading to the strong type opening cylinder chamber 68 of the main cylinder mechanism 28. As a result, the driving force in the backward direction exerted on the main ram 30 is exerted between the pressure receiving plate 14 and the movable platen 18 via the locking ring 78 and the mechanical ram 32, so that the movable platen 18 is largely opened. Exerting force,
The movable mold 22 and the fixed mold 20 are strongly opened between the movable platen 18 and the fixed platen 12.

After that, the fixed mold 20 and the movable mold 22.
After strongly opening the mold by a predetermined amount, the high-speed mold opening operation is started. In such a high-speed mold opening operation, the supply of pressure oil from the pressure boosting cylinder mechanisms 96, 96 to the main cylinder mechanism 28 is released, and the locking ring 78 mounted on the main ram 30 is disengaged. It is rotated by 90 to bring the locking ring 78 into a non-locking state with respect to the mechanical ram 32 (a state in which the meshing tooth 86 of the mechanical ram 32 and the meshing tooth 88 of the locking ring 78 do not mesh with each other). By holding the mechanical ram 32 in the unlocked state, the mechanical ram 32 and thus the movable platen 18 can be freely displaced with respect to the main ram 30. Then, under such a state, the right and left rotating plates 46 are moved by the mold opening / closing motor 26.
By rotationally driving a and 46b and actuating the link mechanism 24, the movable platen 18 is subjected to mold opening displacement, and passes through the intermediate position as shown in FIG. 1 and then as shown in FIG. The movable platen 18 is driven and displaced to the mold open position. Thereby, the high speed mold opening operation is completed, and the molded product is released and taken out.

As is well known, the molding operation of the resin product as described above is repeated continuously as many times as necessary. Further, the stroke of the mold opening / closing operation at a high speed can be appropriately set within the maximum stroke range of the movable platen 18 according to the size of the mounted mold, the size of the molded product, and the like. Furthermore, when shifting from the high-speed mold closing operation to the mold clamping operation, the locking ring 78 is pivotally operated to engage the meshing tooth 86 of the mechanical ram 32 with the meshing tooth 88 of the locking ring 78. Stop ring 78
And a detection means for detecting the relative position of the mechanical ram 32 in the direction of the central axis 44 of the mold clamping, and after adjusting the relative position of the locking ring 78 and the mechanical ram 32, the locking ring 7 is adjusted.
8 is rotated so that the meshing tooth 86 of the mechanical ram 32 meshes with the meshing tooth 88 of the locking ring 78. As such a detection means, for example, a rotary encoder or a linear encoder can be adopted, and based on a preset reference meshing position, it is possible to calculate the closest meshable position to the mold closing completion position. Specifically, the method described in Japanese Patent Application Laid-Open No. 2001-30322 can be preferably adopted.

In the mold clamping device as described above, by providing the pair of pressure boosting cylinder mechanisms 96, 96 each including the pair of pressure boosting pistons 108, 108, one pressure boosting piston 108 is provided. Even if the diameter and the stroke are reduced, it is possible to obtain a large effective piston area and effective piston stroke as a whole with the four booster pistons 108, and thereby, each one booster piston 1 can be obtained.
08, while effectively suppressing the drive force and stroke required for 08, the cylinder chambers 110, 110 of the booster cylinder mechanisms 96, 96
It is possible to generate a large pressure oil in the
It is possible to secure a sufficient amount of oil with a compact structure.

Further, in this embodiment, since the pressure-increasing piston 108 of the pressure-increasing cylinder mechanism 96 is driven by the eccentric plate cam 126, the eccentric plate cam is used as compared with the case where a crank mechanism or the like is used for the drive system. By changing and setting the shape of 126, the drive speed and pattern of the pressure boosting piston 108 can be easily adjusted and set with a large degree of freedom.

Further, in the present embodiment, the four tie bars 16 to which the eccentric plate cams 126 are respectively mounted are provided with the connecting frame body 124 for reinforcement at the tip end portions projected from the eccentric plate cams 126 and the drive gears 130. Since they are connected and fixed to each other, the rigidity against the driving reaction force of the pressure boosting cylinder mechanism 96 that acts on the eccentric plate cam 126 is advantageously ensured, and the operation stability of the pressure boosting cylinder mechanism 96 including the eccentric plate cam 126 is stabilized. Can be improved.

Further, in the present embodiment, the locking ring 78 is disengaged from the mechanical ram 32 during the mold opening / closing operation, so that the pressure receiving plate 14 and the movable plate 18 are substantially connected only by the link mechanism 24. Since the movable platen 18 is electrically driven by the operation of the link mechanism 24, the interlocking of the main cylinder mechanism 28 is avoided, and the mold opening / closing operation can be performed at high speed with excellent energy efficiency.

Moreover, in the present embodiment, a large drive by the pair of pressure boosting cylinder mechanisms 96, 96 (main cylinder mechanism 28) exerted between the pressure receiving plate 14 and the movable plate 18 during the mold clamping operation and the strong mold opening operation. The force is directly exerted between the pressure receiving plate 14 and the movable platen 18 via the connecting mechanism 34 including the meshing teeth 88 of the locking ring 78 and the meshing teeth 86 of the mechanical ram 32, so that the link mechanism 24 is operated. Since a large mold clamping force and a strong mold opening force are not passively exerted, the load bearing strength of the link mechanism 24 can be reduced, and the link mechanism 24 can be made lighter and more compact. In addition, the durability can be advantageously secured.

Therefore, in the mold clamping device of the present embodiment having the above-mentioned structure, therefore, the simple link mechanism 2 is used.
The mold opening / closing operation at a high speed by No. 4 and the mold clamping operation at high pressure and the strong mold opening operation by the pair of pressure boosting cylinder mechanisms 96, 96 mounted on the pressure receiving plate 14 can be realized at the same time.

Further, in this embodiment, the eccentric plate cam 126 is used.
Since the drive gear 130 as a transmission gear is fixedly mounted on the rotation center axis of the above, and the drive gear 130 is rotatably supported by the tie bar 16 together with the eccentric plate cam 126, such a configuration is adopted. By using the drive gear 130 as the transmission gear, the drive system of the eccentric plate cam 126 by the cam drive motor (138) is realized more advantageously.

Although one embodiment of the present invention has been described in detail above, this is merely an example, and the present invention is
Depending on the specific description in such an embodiment,
The present invention is not limited to the interpretation, and can be implemented in a mode in which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art, and such an embodiment deviates from the spirit of the present invention. It goes without saying that all are included in the scope of the present invention unless otherwise specified.

For example, although the four eccentric plate cams 126 have the same shape and size in the above embodiment, the shape and size of the eccentric plate cams 126 may be different from each other as necessary. It is also possible. This is because even if the plurality of eccentric plate cams are not driven in synchronization with each other, pressure oil is generated in the cylinder chamber 110 by independent driving of each eccentric plate cam.

Further, the interlocking drive gear 136 and the drive gear 1
Of course, it is also possible to drive each of the plurality of eccentric plate cams 126 independently without providing the interlocking mechanism including 30.

Further, the specific structure of the pressure boosting cylinder mechanism 96 is not limited to the one provided with the specific mold clamping drive means and the strong mold opening drive means as illustrated, and particularly as the strong mold opening drive means. It is also possible to adopt a hydraulic pump that is a separate structure from the mold clamping device, or can be used as a mold opening / closing drive mechanism.

Incidentally, FIG. 10 shows a concrete example different from the above embodiment as a die opening hydraulic pump mechanism for supplying hydraulic oil to the strong die opening cylinder chamber 68 of the main cylinder mechanism 28 at the time of strong die opening. It is shown. The hydraulic pump mechanism 144 for mold opening uses a rocker arm 150 which is swingably supported by the pressure receiving plate 14 for a pump piston 148 of a plunger type hydraulic pump 146 fixedly mounted on the outer peripheral surface of the pressure receiving plate 14. It is designed to drive. That is, the drive side cam follower 152 is attached to one swing end of the rocker arm 150, and the drive side cam follower 152 is eccentric plate cam 154 rotated by an electric motor (not shown).
The rocker arm 150 is rockably driven around the rocking shaft 156 by being slidably brought into contact with the outer peripheral surface of the rocker arm 150. A driven cam follower 158 is attached to the other swing end of the rocker arm 150, and the driven cam follower 158 drives the rocker arm 150 to drive the pump piston 148 of the plunger type hydraulic pump 146. The pressure oil is directly driven to the strong mold opening cylinder chamber 68 of the main cylinder mechanism 28 by being pressed and driven.

Further, when a plurality of hydraulic cylinder mechanisms are used as the mold clamping drive means and the mold opening drive means for exerting the mold clamping force and the strong mold opening force on the movable platen 18, the hydraulic cylinders having different sizes and structures from each other are adopted. A mechanism may be adopted. Furthermore, the mold opening / closing force by the link mechanism can be made to act together with the driving force of the main cylinder mechanism 28 during the mold clamping operation or the strong mold opening operation.

Further, as the connecting means for connecting the movable plate to the pressure receiving plate so as to be engageable / disengageable, in addition to the engagement / disengagement mechanism using the saw tooth shaped meshing teeth as shown in the figure, the meshing of a rectangular tooth shape, a trapezoidal tooth shape, etc. An engagement / disengagement mechanism using teeth, or an engagement / disengagement mechanism using an engagement hole and an engagement pin can be adopted. Even when an engagement / disengagement mechanism using interlocking teeth is adopted, a plurality of locking rings 78 are circumferentially arranged. It is also possible to adopt a divided structure.

Further, these pressure increasing cylinder mechanisms 96 may be provided not on the pressure receiving plate 14 but on the device base 10. Further, in a molding machine of the type without the pressure receiving plate 14, it may be provided on a fixed plate or the like (fixed plate or movable plate). That is, it is desirable that the pressure increasing cylinder mechanism 96 be provided on the fixed plate or the movable plate on the side on which the mold clamping hydraulic cylinder is provided. Further, when the booster cylinder mechanism 96 is provided on the stationary platen, it is possible to provide a cam mechanism on the tie bar.

[0068]

As is apparent from the above description, in the mold clamping device having the structure according to the present invention, the pressure-increasing cylinder mechanism having the specific structure including the pair of pressure-increasing pistons driven by the eccentric plate cams. By adopting to drive the mold clamping hydraulic cylinder mechanism, it is possible to mount this booster cylinder mechanism on the equipment body such as pressure receiving plate and equipment base while securing a sufficient amount of oil with a compact structure. You can do it.

[Brief description of drawings]

FIG. 1 is a front view schematically showing an intermediate state of a mold opening / closing operation of a mold clamping device as an embodiment of the present invention.

FIG. 2 is a front view schematically showing the maximum mold opening state of the mold clamping device shown in FIG.

FIG. 3 is a front view schematically showing a minimum mold closed state of the mold clamping device shown in FIG.

FIG. 4 is an explanatory view showing an enlarged vertical section in FIG.

5 is an explanatory diagram showing an enlarged plan view of FIG. 3. FIG.

6 is a sectional view taken along line VI-VI in FIG.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a cross-sectional view showing a connecting mechanism as a connecting means in the mold clamping device shown in FIG.

FIG. 9 is a cross-sectional explanatory view showing an enlarged main part of the present invention.

10 is a vertical cross-sectional explanatory view schematically showing one specific example of the hydraulic pump mechanism for mold opening that can be adopted in the mold clamping device shown in FIG. 1. FIG.

[Explanation of symbols]

10 Equipment base 12 fixed plate 14 Pressure plate 18 movable plate 24 link mechanism 28 Main cylinder mechanism 96 Booster cylinder mechanism 104 Booster cylinder 108 Booster piston 126 Eccentric plate cam 138 Pump Motor

Claims (8)

[Claims] 1. A fixed platen and a movable platen are arranged so as to face each other on the device base, and the movable platen is moved closer to the fixed platen.
A mold opening / closing drive mechanism for moving the movable platen in a separating direction to open and close the movable platen at high speed with respect to the fixed platen is provided, and a mold closing mechanism for moving the movable platen close to the fixed platen by the mold opening / closing drive mechanism is provided. In a mold clamping device provided with a mold clamping hydraulic cylinder mechanism that exerts a mold clamping force between the movable plate and the fixed plate to perform a mold clamping operation under a state, the device base directly or indirectly through a fixed plate or the like. A pressure boosting cylinder mechanism is constructed by slidably fitting a pair of pressure boosting pistons on both sides in the axial direction of the pressure boosting cylinder supported by the pair of eccentrics that press and drive the pair of pressure boosting pistons from the outside. A plate cam and a cam driving motor are provided, and the cam driving motor drives the pair of pressure-increasing pistons through the pair of eccentric plate cams to generate the pressure-increasing cylinder mechanism. A mold clamping device characterized in that the hydraulic pressure to be applied is guided to the mold clamping hydraulic cylinder mechanism to perform the mold clamping operation. 2. The mold clamping device according to claim 1, further comprising an interlocking mechanism that rotationally drives the pair of eccentric plate cams by interlocking with each other. 3. A plurality of pressure boosting cylinders in which the pair of pressure boosting pistons are slidably fitted are provided, and a driving force is applied to each pair of pressure boosting pistons slidably fitted in the respective pressure boosting cylinders. The mold clamping device according to claim 2, wherein a plurality of the eccentric plate cams that exert a force are driven to rotate by interlocking with each other by the interlocking mechanism. 4. A coil spring is housed in the pressure boosting cylinder, and a biasing force of the coil spring is applied in a direction in which the pair of pressure boosting pistons slidably fitted in the pressure boosting cylinder are separated from each other. The mold clamping device according to any one of claims 1 to 3, which is always applied. 5. A return type cylinder mechanism is adopted as the mold clamping hydraulic cylinder mechanism, and the hydraulic pressure generated by the pressure increasing cylinder mechanism is selectively applied to a plurality of cylinder chambers provided in the mold clamping hydraulic cylinder mechanism. 5. The mold clamping hydraulic cylinder mechanism causes the movable platen to move in both directions of approaching and separating from the fixed plate, thereby performing a mold clamping operation and a strong mold opening operation. Mold clamping device. 6. A pressure receiving plate is disposed on the apparatus base so as to be opposed to the fixed plate at a predetermined distance from each other, and the pressure receiving plate is arranged in parallel to each other across the fixed plate and the pressure receiving plate. A plurality of extending tie bars are arranged to guide the movement of the movable plate between the fixed plate and the pressure receiving plate by the tie bars, while the pressure receiving plate is provided with the mold clamping hydraulic cylinder mechanism. The pressure-increasing cylinder is provided so as to extend between two tie bars that are adjacent to each other in the circumferential direction of the board, and the pair of the pair of pressure-increasing cylinders that are opened toward the two tie-bars are provided at openings on both sides in the axial direction of the pressure-increasing cylinder. The pressure boosting cylinder mechanism is configured by fitting the pressure boosting piston, and the pair of eccentric plate cams that exert a driving force on the pair of pressure boosting pistons are rotatable using the two tie bars, respectively. The mold clamping device according to any one of claims 1 to 5, which is supported. 7. A reinforcing member for connecting and reinforcing the tie bars supporting the pair of eccentric plate cams is provided, and the eccentric plate cam is disposed between the reinforcing member and the pressure receiving plate in the tie bar. The mold clamping device according to claim 6. 8. A connecting means for connecting the mold clamping piston of the mold clamping hydraulic cylinder mechanism provided on the pressure receiving plate to the movable plate so as to be engageable with and disengageable from, and release the engagement by the connecting means. Then, while the movable platen is disengaged from the pressure receiving plate, the movable platen is opened and closed at high speed by the mold opening / closing drive mechanism, and the movable plate is engaged with the pressure platen by the connecting means. The mold clamping device according to claim 6 or 7, wherein a driving force by the mold clamping hydraulic cylinder mechanism is exerted on the movable platen via the connecting means to cause the mold clamping operation.