JP3159040B2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for obtaining a molded product by injecting a resin material into a mold in a molten state.

[0002]

2. Description of the Related Art As an injection molding machine for injecting a resin material into a mold in a molten state to obtain a molded article, as shown in FIG. 9, a first mold 81 and a first mold 81 which are joined to each other to define a cavity. A second die 82, a first mounting plate 84 to which the first die 81 is mounted and fixed to the machine base 83, and a second die 82 are mounted, and the second die 82 is A second mounting plate 85 movably provided with respect to the machine base 83 so as to be joined to and separated from the one die 81; a plate moving driving means 86 for moving the second mounting plate 85; In addition to being provided on the side opposite to the mold mounting surface of the plate 84, the plate 84 is provided so as to be movable relative to the machine base 83 so as to approach and separate from the first mounting plate 84, and further in a state in which the plate 83 is in contact with the first mold 81. In the cavity An injection device 87 for injecting the fat material,
An injection device movement driving means (not shown) for moving the injection device 87 relative to the machine base 83 is generally employed. As a plate moving drive unit 86 of this type of injection molding machine, a hydraulic cylinder is provided directly on the side opposite to the mold mounting surface of the second mounting plate 85, or via a toggle mechanism 89 as shown in FIG. It is general that the hydraulic cylinder is configured by mounting. As a special example, as shown in Japanese Patent Publication No. 7-29340, a hydraulic cylinder is mounted on the first mounting plate side of the movable second mounting plate. Some are constructed by attachment.

[0003]

Since the injection device 87 is disposed on the side opposite to the mold mounting surface of the first mounting plate 84 fixed to the machine base 83, the molded product protruding device is provided. To the first mounting plate 84 is difficult. Therefore, when the mold is opened, the molded product is generally left in the second mold 82 on the movable side and is projected by the molded product projecting device of the second mounting plate 85. By the way, when a molded product remains in the movable second mold 82, in any of the conventional injection molding machines described above,
When removing the remaining molded product using an unloader,
Second mounting plate 85 to which the second mold 82 is mounted
The stop position when the mold is opened must be made constant. For this reason, conventionally, a mechanical stopper is provided at the stop position of the second mounting plate 85, and control such as greatly reducing the moving speed of the second mold mounting plate near the stop position is performed. The variation in the stop position of the second mold mounting plate 85 is eliminated, but in this case, the time required for opening the mold becomes longer, and thus the problem that productivity is reduced and the cost is increased. was there. Further, every time the mold opening stroke is changed, it is necessary to change the chucking position of the unloader and adjust the position of the stopper, resulting in poor workability. Accordingly, an object of the present invention is to provide an injection molding machine which can be manufactured at low cost and can improve productivity and workability even when a molded product is taken out by an unloader.

[0004]

Means for Solving the Problems To achieve the above object, the invention according to claim 1 is fixed to a machine base,
A first mounting plate on which a fixed mold is mounted on one side surface, and a moving mold that is joined to the fixed mold to define a cavity is mounted on a side surface facing the first mounting plate, and Join the mold to the fixed mold
A second mounting plate movably provided with respect to the machine base to be separated, and provided at a position opposite to the mold mounting surface of the second mounting plate, and with respect to the first mounting plate. An injection device that is movably supported by the machine base so as to approach / separate from the machine base, and that injects the resin material into the cavity while being in contact with the moving mold; and an injection device that moves the injection device relative to the machine base. The device moving drive means and the second mounting plate are integrally connected to the injection device.
And a connecting member to be connected .
Thus, the position of the molded product remaining on the fixed first mounting plate does not fluctuate as in the related art. Therefore, even when the remaining molded product is taken out using the take-out machine, the take-out position does not change.

According to a second aspect of the present invention, in the first aspect, the fixed die is provided so as to be movable inside the outer die attached to the first mounting plate. An inner mold moving drive that separates the inner mold from the movable mold on the side opposite to the mounting surface of the fixed mold on the first mounting plate, while dividing the inner mold into an inner mold that defines a cavity. It is characterized in that means are provided. Thereby, at the time of molding and mold release of the molded product, the inner mold moving drive means joins and separates only the inner mold of the first mold to and from the second mold. Therefore, it is not necessary to move the second mounting plate and the second mold since the state of being joined to the outer mold can be maintained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an injection molding machine according to the present invention will be described below with reference to FIGS. The injection molding machine has a substantially rectangular parallelepiped shape, and a machine base 11 installed on a floor or the like with a longitudinal direction along a horizontal direction (the left-right direction in FIGS. 1 and 2), and A first mounting plate 12 having a rectangular shape fixed to one side in the longitudinal direction so as to be orthogonal to the longitudinal direction, and a conventionally known slide mechanism 13 attached to the other side in the longitudinal direction on the machine base 11; ,
A moving section 14 mounted on the slide mechanism 13 so as to be movable only in a direction along the longitudinal direction of the machine base 11. A first mold (fixed mold) 16 is attached to the first mounting plate 12 on the side of the moving section 14.

The moving unit 14 includes a base 17 mounted on the slide mechanism 13 and a moving cylinder such as a hydraulic cylinder disposed on the base 17 along the longitudinal direction of the machine base 11 in the axial direction. (Injection device moving drive means) 18, and these moving cylinders 18 are, as shown in FIG. 3, a cylinder body 19 fixed to the base 17 at one diagonal position as a center of an injection device 23 described later. , By controlling the supply of pressure oil in the cylinder body 19,
And a piston rod 20 whose amount of protrusion from the piston changes. The tip of the protruding side of the piston rod 20 of each moving cylinder 18 is fixed to the first mounting plate 12 via a nut. The number of the moving cylinders 18 is not limited to two, and three or more moving cylinders 18 may be equally distributed around the center of the injection device 23.

The moving section 14 is located between the moving cylinders 18 and is provided with a resin material in a molten state at the tip of a nozzle section 22.
An injection device 23 is provided in a state where the nozzle portion 22 faces the first mounting plate 12 side.
The injection device 23 includes a heating cylinder 24 fixedly connected to the base 17 while the nozzle 22 is connected and fixed to the tip, and is maintained in a heated state so as to melt the resin material. The screw (not shown) inserted inside the heating cylinder 24 is moved in the axial direction to inject the molten resin material stored in the nozzle portion. A cylinder 25, a hopper 26 for externally supplying a resin material into the heating cylinder 24, and an extended shaft of the screw inserted into the injection cylinder 25, and the resin supplied from the hopper 26 by rotating the screw. A screw rotation driving device 27 such as a hydraulic motor for feeding the material to the tip end side of the screw.

The moving unit 1 including the injection device 23
4 is farthest from the first mounting plate 12 with the moving cylinder 18 most protruding the piston rod 20, and with respect to the first mounting plate 12 with the moving cylinder 18 most retracting the piston rod 20. It moves with respect to the machine base 11 so as to be closest.

A rectangular second mounting plate 29 is provided between the cylinder body 19 of the moving cylinder 18 and the first mounting plate 12. The second mounting plate 29 is supported by the piston rod 20 of each moving cylinder 18 so as to be movable only in the axial direction thereof in a state parallel to the first mounting plate 12. It is movable with respect to the machine base 11 using the guide shaft 20.

The second mounting plate 29 is formed with an insertion hole 30 through which the nozzle portion 22 of the injection device 23 is inserted. The mold 31 is fixed. The position of the second mold 31 in the direction orthogonal to the moving direction is aligned with the position of the first mold 16, and the movement of the second mounting plate 29 to the first mounting plate 12 side causes the first die 16 to move to the first mounting plate 12 side. The first mold 16 is joined to the mold 16 to define a cavity (not shown) therein, and the second attachment plate 29 is moved in a direction opposite to the first attachment plate 12 to move the second attachment plate 29 in the opposite direction. Separated from one mold 16. Here, the second mold 31 is brought into contact with the nozzle portion 22 of the injection device 23 from the insertion hole 30 side to communicate the nozzle portion 22 with the cavity, thereby being ejected from the nozzle portion 22. Resin is filled in the cavity.

The second mounting plate 29 has a nozzle 2
2 is brought into contact with the second mold 31 while the nozzle 22
A connecting member (connecting means) 35 that locks the flange 34 formed on the second mounting plate 29 and integrally connects the second mounting plate 29 to the injection device 23 is attached with a bolt or the like. The connecting member 35 has a cylindrical portion 36 and an inner flange 37 projecting inward from one end of the cylindrical portion 36.
The flange 34 is locked by the inner flange 37. In addition,
In order to enable attachment / detachment, the connecting member 35 is divided into two parts by a cut surface including the axis, and when the connecting member 35 is removed from the second mounting plate 29, the second mounting plate 29 It is possible to move independently of the injection device 23.

Next, an injection molding process performed by the injection molding machine having the above configuration will be described. In a state where the second mounting plate 29 and the nozzle portion 22 of the injection device 23 are integrally connected by the connecting member 35, the piston rod 20 is moved by the two moving cylinders 18 in the direction of being pulled into the cylinder main body 19, and FIG. As shown in (2), the injection device 23 and the second mounting plate 29 are integrally moved in the direction of the first mounting plate 12, and the second die 31 is joined to the first die 16. Stop. In this state, the injection device 23
When the resin material in a molten state is injected from the nozzle portion 22 by using the first mold 16 and the second mold 31
And is filled in a cavity (not shown) defined by the above.

After a cooling time sufficient for the molten resin to be solidified in the cavity has elapsed, the two moving cylinders 1
8, the piston rod 20 is driven in a protruding direction, and as shown in FIGS. 1 and 2, the injection device 23 and the second mounting plate 29 are integrally integrated with the first mounting plate 1.
The second mold 31 is moved away from the first mold 16 by moving the second mold 31 away from the first mold 16 and stopped at a predetermined position.
In this opened state, the molded product is placed on the first mold 16 on the side opposite to the injection device 23, that is, on the first mounting plate 12 side.
And take it out with an unillustrated unloader. The above steps will be repeated.

According to the injection molding machine having the above structure, the first mounting plate 12 to which the first die 16 is mounted is fixed, so that the molded product remaining in the first die 16 can be removed. Also when taking out using an unloader, a take-out position does not change. Therefore, it is not necessary to provide a mechanical stopper or the like for keeping the removal position of the molded product constant, or to perform a significant deceleration control at the stop position of the second mounting plate. Since the position adjustment and the like are not required, the cost can be reduced and the productivity and workability can be improved. In the above, the piston rod 20 of the moving cylinder 18 is extended as an integral part to the first mounting plate 12 and functions as a guide shaft of the second mounting plate 29. The guide shaft is separate from the piston rod 20. And both may be integrally connected by a connecting tool. The moving cylinder 18 is constituted by a hydraulic cylinder. Instead, a mechanism for converting the rotation of a hydraulic motor or an electric motor into a linear motion by a screw (ball screw) and a nut, or an apparatus called an electric cylinder May be connected to the rod 20 described above.

Next, a second embodiment of the injection molding machine of the present invention will be described below with reference to FIGS. 5 to 7 focusing on the differences from the first embodiment. In the injection molding machine according to the second embodiment, a first die (fixed die) 16 is mounted on a first mounting plate 12, and a machine base 1 is provided at the center.
An outer mold 42 having a through hole 41 formed along the longitudinal direction of the outer mold 42
And an inner die 43 fitted into the through hole 41 of the outer die 42 so as to be movable along the longitudinal direction of the machine base 11. The inner mold 43 includes a second mold (moving mold) 3
The cavity 45 is defined in a state where the cavity 45 is in contact with 1.
The outer mold 42 is irrelevant to the definition of the cavity 45.

On the side of the second die 31 of the outer die 42, a groove 44 for opening the lower part of the through hole 41 in the state of contact with the second die 31 is formed in the cavity 45. The groove width is formed to be larger than the width dimension (or diameter dimension), so that the molded product can drop freely from the groove 44. The second mold 31 may be formed as a single mold as in the first embodiment, but may be formed into an outer mold and an inner mold as in the first mold 16. A split configuration may be used. In the case of the latter configuration, the inner mold 46 that joins with the inner mold 43 of the first mold 16 to define the cavity 45 is formed.
And an outer mold 4 outside thereof, which is unrelated to the definition of the cavity.
7, which are fixed to each other while being attached to the second mounting plate 29. That is, the outer mold 4
7, a stepped through hole 47a having a large diameter on the side of the second mounting plate 29 is formed along the longitudinal direction of the machine base 11, and a small diameter sprue bush is formed in the through hole on the side of the mounting plate 29. An inner mold 46 having a large-diameter flange 46b and a large-diameter flange 46b is fitted with the flange abutting on the step of the through-hole, and the sprue bush 46a is parallel to the insertion hole 30 of the second mounting plate 29. While being fitted into the hole 30a, the flange 46b is sandwiched between the second mounting plate 29 and the step of the stepped through hole 47a,
An outer mold 47 is fixed to the second mounting plate 29 with bolts or the like. Although not shown, the outer die 47 is prevented from rotating around the inner die 46 by a key, a set screw or the like.

As shown in FIG. 7, a positioning hole 49 penetrating along the longitudinal direction of the machine base 11 is formed in the inner die 43 of the first die 16. The other end of a positioning rod 50 having one end fixed to the inner mold 46 of the second mold 31 is slidably fitted. The inner holes 43 and 46 are mutually connected by the positioning holes 49 and the positioning rod 50. Are positioned so that the positional relationship in the circumferential direction does not change.

The first mounting plate 12 is formed with a hole 52 into which the inner die 43 can be inserted. The hole 52 for moving the inner die 43 to the opposite side of the second mounting plate 29 is provided. An inner moving cylinder (inner moving driving means) 53 such as a hydraulic cylinder is provided. The inner die moving cylinder 53 is controlled by a cylinder body 54 fixed to the first mounting plate 12 on the opposite side to the second mounting plate 29 and a supply of pressurized oil before and after a piston 55a of the cylinder body 54. And a piston rod 55 whose projection from the cylinder body 54 changes. The piston rod 55 is formed to have a smaller diameter than the hole 52 of the first mounting plate 12, and the first mounting plate The tip on the 12th side is fixed to the inner mold 43 through the hole 52 via a screw 55a. The inner mold moving cylinder 53 joins the inner mold 43 to the inner mold 46 of the second mold 31 when the outer rod 42 is in contact with the second mold 31 and the piston rod 55 is most protruded. When the piston rod 55 is fully retracted in this state, the inner mold 43 is inserted into the hole 52 and separated from the inner mold 46 of the second mold 31.

The piston 55a of the inner moving cylinder 53
Has a cylinder 55A formed therein, and a piston 56a driven by hydraulic pressure or the like is provided inside the piston 55.
The piston 55a and the piston 55a and the piston rod 56 constitute an ejector cylinder device 57. On the piston 55a, a rod 55c protruding outside the inner mold moving cylinder 53 is integrally attached to the opposite side of the piston rod 55. Are provided with a pair of pressure oil supply / discharge paths 55d and 55e communicating with each other. These supply / discharge paths are connected to a hydraulic source via a switching valve (not shown). The piston rod 56 is connected to the piston rod 5
In the state where the inner die 43 is joined to the inner die 46 of the second die 31, the shaft hole 55 b penetrated to the center of the inner die 5 and the through hole 58 penetrating the center of the inner die 43 are inserted. In the most retracted position, the front end surface is flush with the protrusion of the inner mold, defines a part of the cavity 45 forming the shape of the molded product 60, and connects the inner mold 43 to the second mold 31. If the molded product 60 remaining in the inner mold 43 is most protruded from the piston rod 55 while being separated from the inner mold 46,
It is designed to withdraw from.

Next, the injection molding process performed by the injection molding machine having the above configuration will be described. In the state where the second mounting plate 29 and the nozzle portion 22 of the injection device 23 are integrally connected by the connection member 35 as in the first embodiment, the injection is performed by the two moving cylinders 18 as shown in FIG. The device 23 and the second mounting plate 29 are integrally moved in the direction of the first mounting plate 12, and the outer mold 47 of the second mold 31 is joined to the outer mold 42 of the first mold 16. While the internal piston rod 56 is retracted, the piston rod 5 of the inner mold moving cylinder 53 is stopped.
5 is projected toward the first mounting plate 12, and the inner mold 43 is also joined to the inner mold 46 of the second mold 31. In this state,
When the molten resin material is injected from the nozzle portion 22 by the injection device 23, the resin material is defined by the inner mold 43 of the first mold 16 and the inner mold 46 of the second mold 31. The sprue 46 of the sprue bush 46a is placed in the cavity 45.
Filled through c.

After a sufficient cooling time for the molten resin to solidify in the cavity 45, the injection device 23
And without moving the second mounting plate 29
The inner die 43 is drawn into the hole 52 by the inner die moving cylinder 53 and separated from the inner die 46 of the second die 31. In this opened state, the molded product 60 is detached from the inner mold 43 by projecting the piston rod 56 of the ejector cylinder device 57, and through the groove 44 of the outer mold 42 joined to the second mold 31. And drop it on the machine base 11.

Thereafter, the inner die 43 is moved in the direction of the second die 31 by the inner die moving cylinder 53 without moving the injection device 23 and the second mounting plate 29 with respect to the machine base 11. The steps of joining the inner mold 46 of the second mold 31 and performing injection molding, separating only the inner mold 43 from the second mold 31 and releasing the molded product 60 are repeated. In addition, each inner mold 43,
If necessary, such as replacing 46 or cleaning molds 16 and 31,
The second mounting plate 29 is moved by the moving cylinder 18 together with the injection device 23 with respect to the machine base 11.

According to the injection molding machine having the above-described configuration, as described above, the inner die 43 of the first die 16 is moved by the inner die moving cylinder 53 during the molding and the release of the molded product 60. If the outer mold 47 of the second mold 31 is joined to and separated from the inner mold 46 of the first mold 16, the state in which the outer mold 47 of the second mold 31 is joined to the outer mold 42 of the first mold 16 can be maintained. It is not necessary to move the mold 31 and the second mounting plate 29. Therefore, when the molded product 60 is released from the mold, it is possible to cope with the movement of the inner mold 43 alone. Therefore, the molding cycle can be further shortened, and the productivity can be further improved.

Moreover, the first mounting plate 12 for supporting the first mold 16 on which the molded product 60 remains when the mold is opened is fixed to the machine base 11, and the first mounting plate 12
Since a mechanism for moving the inner cylinder 53 and the ejector cylinder device 57 as described above can be easily arranged, a space can be secured around the first mounting plate 12 as is apparent from the drawing. can do.
Further, since the first mold 16 is divided into the inner mold 43 and the outer mold 42 and the second mold 31 is divided into the inner mold 46 and the outer mold 47, the shape of the molded product 60 is changed by using each mold. Does not need to be changed, and can be dealt with by changing only each of the inner dies 43 and 46. Therefore, the outer mold 4 can be used for various molded products 60.
2, 47 can be shared. In addition, by increasing the pressure of the inner mold 43 in contact with the inner mold 46 of the second mold 31, it is possible to apply a higher compressive force to the molded product 60 at the time of molding.

In the second embodiment,
Although the case where the flange 34 of the nozzle portion 22 is locked by the connecting member 35 and the second mounting plate 29 is connected to the injection device 23 has been described as an example, the third embodiment shown in FIG. As in the form, the moving cylinder 18
In a state where the piston rod 20 is inserted, the flange portions at both ends are connected to the cylinder body 19 and the second mounting plate 29 by using a cylindrical or polygonal cylindrical connecting member 62 attached to the second mounting plate 29 with bolts or the like. It is also possible to connect the mounting plate 29 with the injection device 23. in this case,
In order to enable attachment / detachment, the connecting member 62 is divided into two by a cut surface including the axis. The connecting member 62 has a structure in which various sizes are prepared and the length can be changed so that the connecting member 62 can cope with a change in the contact position of the nozzle portion 22 with the second mold 31. It is also possible.

[0027]

As described above in detail, according to the first aspect of the present invention, the injection device is provided on the side opposite to the mold mounting surface of the second mounting plate movably provided with respect to the machine base. After molding, when the mold is opened by moving the second mounting plate away from the fixed die fixed to the first mounting plate fixed to the machine base by moving the second mounting plate, the molded product Will remain on the fixed mold side. Therefore, even when the remaining molded product is taken out using the take-out machine, the take-out position does not change. Therefore, there is no need to provide a mechanical stopper or the like for keeping the removal position of the molded product constant, or to perform a significant deceleration stop control near the stop position of the second mounting plate. Therefore, even if the mold opening / closing stroke is changed, it is not necessary to adjust the position of the unloader every time, and the workability can be improved.

According to the second aspect of the present invention, only the inner mold of the fixed mold is joined to and separated from the movable mold by the inner mold moving drive means at the time of molding and releasing the molded product. Since the movable mold can be maintained in a state of being joined to the outer mold of the fixed mold, it is not necessary to move the second mounting plate and the movable mold. Therefore, since the release of the molded product can be dealt with only by moving the inner mold in the fixed mold, the inertial force of the movable mold is drastically reduced as compared with the case where the second mounting plate is moved at the time of mold release. And its rapid and smooth movement can further reduce the molding cycle and improve productivity.

[Brief description of the drawings]

FIG. 1 is a plan view showing an opened state of an injection molding machine according to a first embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side view of the same.

FIG. 4 is a plan view illustrating a mold clamping state of the injection molding machine according to the first embodiment of the present invention.

FIG. 5 is a front view showing a mold clamping state of an injection molding machine according to a second embodiment of the present invention.

FIG. 6 is a front view showing a state in which an inner mold of a first mold of an injection molding machine according to a second embodiment of the present invention is opened.

FIG. 7 is a partially enlarged view of FIG.

FIG. 8 is a front view showing a state where an inner mold of a first mold of an injection molding machine according to a third embodiment of the present invention is opened.

FIG. 9 is a front view showing an example of a conventional injection molding machine.

FIG. 10 is a front view showing another example of the conventional injection molding machine.

[Explanation of symbols]

 Reference Signs List 11 machine base 12 first mounting plate 16 first die (fixed die) 18 moving cylinder (injection device moving drive means) 23 injection device 29 second mounting plate 31 second die (moving die) 35, 62 connecting member (connecting means) 42 outer die 43 inner die 45 cavity 52 hole 53 inner die moving cylinder (inner die moving driving means) 60 molded product

Claims (2)

(57) [Claims] A first mounting plate fixed to a machine base and having a fixed mold attached to one side thereof; and a movable mold joined to the fixed mold to define a cavity. A second mounting plate attached to the side surface facing the mounting plate and movably provided to the machine base so as to join and separate the movable mold from and to the fixed mold; and It is provided on the opposite side to the mold mounting surface, and is movably supported by the machine base so as to approach / separate from the first mounting plate. An injection device for injecting the resin material into the cavity; an injection device moving drive unit for moving the injection device with respect to the machine base; and the second mounting plate integrated with the injection device.
An injection molding machine comprising: a connecting member to be connected ; 2. The method according to claim 2, wherein the fixed mold is divided into an outer mold attached to the first mounting plate and an inner mold movably provided inside the outer mold to define the cavity. 2. The injection plate according to claim 1, wherein said mounting plate is provided with an inner die moving drive means for separating said inner die from said movable die on a side surface opposite to a mounting surface of said fixed die. Molding machine.