JPH0435333B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a mold thickness adjusting device used in an injection molding machine for injection molding various resin products into a mold under pressure.

(Prior Art) As a mold thickness adjusting device for an injection molding machine for injecting molten raw materials of various synthetic resin materials into molds to obtain various products with desired shapes and structures, for example, Japanese Patent Application Laid-Open No. 59
Those described in JP-A-62130 and JP-A-59-62129 are known.

This conventional type consists of a fixed mold that is fixed on the frame side of an injection molding machine, and a movable mold that can move forward and backward toward the fixed mold and can be opened and closed, and is held along a tie rod belonging to the frame. A positioning half nut, which is movably disposed in the same direction as the movable mold and also along the tie rod, is moved forward and backward in a direction orthogonal to the tie rod to the threaded part of the tie rod. The threaded portion of the half nut was removably engaged.

(Problem to be Solved by the Invention) In the conventional device, when the half nut is closed, the closing operation is performed without confirming the proper engagement position between the positioning screw portion of the tie rod and the screw portion of the half nut. Ta.

Therefore, if the meshing positions of both screw teeth are not appropriate, there is a problem in that both teeth are damaged, and furthermore, positioning accuracy is deteriorated due to sliding movement of both teeth.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mold thickness adjusting device for an injection molding machine that allows a half nut to be closed in a proper meshing position.

(Means for Solving the Problems) In order to achieve the above object, the present invention takes the following measures. That is, the present invention is characterized by a fixed mold that is fixed on the frame side of an injection molding machine, and a movable mold that can move forward and backward toward the fixed mold and can be opened and closed, and is held along a tie rod belonging to the frame. A positioning half nut is disposed on a positioning thread formed on the tie rod so as to be movable in the same direction as the movable mold and also along the tie rod. The threaded part of the half nut is removably engaged with the threaded part, further comprising: a driving device for moving the half nut relative to the movable type; A detecting member for detecting a proper meshing position of both screw teeth is provided between both screw parts, and a control device is provided for stopping the drive device when the detecting member detects a proper meshing position of both screw teeth.

(Function) According to the present invention, the detection member detects the proper meshing position between the tie rod and the half nut, and the half nut drive device is stopped based on the detection result, so that the half nut can be stopped at the proper meshing position. This allows for no slipping during engagement.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Injection molding machines can be broadly divided into vertical and horizontal types. In a vertical injection molding machine, the mold is divided into a movable mold and a fixed mold vertically up and down, and in a horizontal injection molding machine, the mold is divided into a movable mold and a fixed mold horizontally left and right. The basic structure of both models is the same, and the outline thereof will be explained with reference to FIG. 3.

A frame 1 in an injection molding machine is composed of a bed (fixed platen) 2 fixed to the floor, a top platen 3, and a plurality of (for example, four) tie rods 4 at equal positions connecting both 2 and 3. is,
In the illustrated example, the fixed mold 5, which is a vertical type, is placed on the bed 2 so that it can be replaced and removed, and a slide (movable plate) 6 is mounted on the bed 2 so that it can be raised and lowered over the tie rod 4. The slide 6 is held by the piston rod 7a of the mold opening/closing cylinder 7 installed on the side of the bed 2, and the movable mold 8, which becomes the upper mold, is removably attached to this slide 6. A movable mold 8 faces the fixed mold 5 through the mold and is installed along the tie rod 4 so that it can be raised and lowered and opened and closed.Although not shown, an injection device for molten resin material is connected to one of the molds. . In this example, a plurality of mold clamping cylinders 9 are installed on the slide 6 in a tie-rod penetrating manner to clamp both molds 5 and 8, and the mold clamping cylinders 9 are placed above the mold clamping cylinder 9. A half nut plate 10 is mounted on the tie rod 4 so as to be movable up and down, and a half nut 11 that surrounds the tie rod 4 and constitutes a mold thickness adjustment device is installed on the plate 10 together with a cover 12. be done. If we exclude the function of the mold thickness adjustment device and look at the original main functions of the injection molding machine, as is clear from the illustration, the movable mold 8 is closed to the fixed mold 5 via the opening/closing cylinder 7, and the mold clamping cylinder By clamping both molds with 9 and injecting and filling the molten resin material into the mold under pressure, various products can be obtained depending on the mold surface. When replacing the molds 5 and 8, it is essential to first position the movable mold 8, which is the upper mold, depending on the size and thickness of the molds. For this reason, this injection molding machine uses a mold thickness adjusting device, which will be explained with reference to FIGS. 3 and 4. That is, a positioning screw part 13 in which serrated screw teeth 13a are arranged circumferentially over an appropriate length is formed on the outer circumferential surface of the tie rod 4 at a predetermined position. On the half nut plate 10 which is loosely fitted to the tie rod 4 so as to be movable up and down, a half nut 11 having screw teeth 11a of the same shape as the screw teeth 13a arranged in the center hole and divided into two from the center is placed.
The nut is mounted via a cover 12 so as to be movable in a direction orthogonal to the half nut plate 10, and is movable up and down together with the half nut plate 10. A piston rod 14 of a drive cylinder 14 such as a hydraulic cylinder as a drive member for engagement and disengagement.
a are connected, and the cylinder 14 is installed on the half nut plate 10, whereby each half of the half nut 11 moves forward and backward, and the positioning screw part 13 and the positioning half nut 1
One engagement and disengagement is performed. In addition, in order to raise and lower the half nut plate 10, a screw type jack 15 that rotates up and down as a lifting member is installed on the slide 6 located below the plate 10 via the mold clamping cylinder 9 in the illustrated example. In addition, a gear motor 16 with a brake as a driving member for rotating the jack 15 up and down is also installed on the slide 6, and the motor 16 and the jack 15 are connected by an interlocking mechanism 17 using a chain, sprocket, etc. By doing so, the half nut plate 10 is raised and lowered by rotating the jack 15 in forward and reverse directions.

In the embodiment, a detection member 18 using a magnetic sensor for directly detecting the height of the screw teeth 13a on the positioning screw portion 13 side is fixed at a fixed position on the upper surface of the cover 12.

At the other end of the input shaft of the jacks 15, 15,
As shown in FIG. 2, a rotating disk 24a for detecting the input rotation speed of the jack 15 as a pulse signal.
A detection member 24 consisting of a proximity switch 24b and a proximity switch 24b is installed.
It is possible to detect the amount of movement.

In Figures 1 and 3, reference numeral 19 indicates the slide (movable plate) disposed on the slide (movable plate) 6 side.
a limit switch for detecting the origin, which detects the origin which is the lowering (retreat) limit of the jacks 15, 15 of No. 6;
20 indicates a proximity switch for detecting close contact between the jack 15 and the half nut plate 10, which is disposed on the jack 15 side correspondingly. Also, the first
In the figure, 27 is a limit switch for detecting the opening of the half nut, and 28 is a limit switch for detecting the half nut closed.
1 is in the open or closed position. 30 is a stroke detection switch.

In the configuration shown above, the operation flow when adjusting the mold thickness is as shown in Figure 5, where the equipment operator inputs the thickness of the fixed mold 5 and the movable mold 8 used, and presses the mold thickness adjustment start button. As a result, the jack 15 is started to be driven, the control device 25 equipped with an arithmetic device calculates the necessary amount of rise of the jack 15 from the thickness of both molds 5 and 8, and the detection member 24 detects the input shaft rotation of the jack 15. At the time when it is detected that the number of screw teeth 13a and screw teeth 11a have reached the required movement amount to bring both the screw teeth 13a and the screw teeth 11a to a proper meshing position, the jack 15 is already stopped, and after stopping, the detection member 18, it is detected that both the screw teeth 13a and the screw teeth 11a have reached the proper meshing position, and after confirming that the mechanical operation is safe (interlock), the drive cylinder 1
4 to advance the half nut 11 to the closed position, the screw teeth 13a, 11a can be smoothly engaged with each other without resistance. The half nut plate 10 is moved by the jack 15, and both teeth 11a, 1 are brought into contact with each other under pressure, albeit at a low pressure.
3a do not shift their positions in a twisted manner and engage with each other, thereby eliminating damage to both screw teeth 11a and 13a, and preventing the jack 15 and drive cylinder 14 from being damaged.
By reducing the burden on the device, the device can be made more compact. Furthermore, the equipment operator can automatically adjust the mold thickness by simply inputting the thickness of both molds 5 and 8 as data into the control device 25, which significantly improves work efficiency and shortens work time. It will be done.

In the vertical injection molding machine, in addition to this embodiment, the half nut 1 is placed on the top platen 3.
There is also a type in which a moving mechanism is installed for 1, and a stopper or nut that can be raised and lowered is operated on the half nut plate 10 side, and the half nut 11 is provided on the lower side of the slide (movable plate) 6 instead of the upper side. Some machines are equipped with a half nut plate 10 and a positioning screw part 13, but the present invention can of course be applied to these as well.Furthermore, in horizontal injection molding machines, basically the one shown in the figure is turned over by 90 degrees. It will face the bed (fixed plate) 2 and the slide (movable plate) 6 in the horizontal direction, but in the horizontal type, the tie rod 4 penetrates the bed (fixed plate) 2 and connects the ram of the mold clamping cylinder. There is a type that doubles as a piston rod, or a type where one end of the tie rod 4 is inserted through the bed (fixed plate) 2, and a half nut 11 is provided on the side of the bed (fixed plate) 2 surrounding the one end of the insertion. However, the mold thickness adjusting device of the present invention can be applied to any of these.

In the embodiment, a direct detection type magnetic sensor was used as the detection member 18, but it is equally effective to use a high precision displacement meter instead of the magnetic sensor, and as illustrated in FIGS. 6 and 7. As an indirect known means, the light transmission hole 21 is formed under the correct meshing pitch interval L between the screw tooth 13a of the positioning screw portion 13 and the screw tooth 11a of the half nut 11.
It is also possible to arrange a dummy plate 22 for detecting the engagement position between the two, and to use a photoelectric sensor 23 or a magnetic sensor with a light emitting part 23a and a light receiving part 23b, and the detection member 18 can be used freely. In addition to the screw type jack, an electric jack or a fluid pressure cylinder equipped with means (locking means) for securing forward and backward positions of the ram or piston rod can be used as the driving member for moving the half nut plate 10. .

Further, as an alternative to the detection member 24 that detects the number of rotational pulses of the rotation axis of the jack 15, the amount of movement of the half nut plate 10 can be detected as a pulse using a magne scale or a linear scale arranged in parallel along the tie rod 4. is also possible,
Furthermore, by using a servo motor or a pulse motor to drive the jack 15, it is also possible to drive and raise the jack 15 by a designated movement amount.

(Effects of the Invention) According to the present invention, problems in the prior art in this type of injection molding machine can be solved, namely, the positioning screw portion 1
3 and both screw teeth 13 on the half nut 11
It is extremely effective in solving problems such as forced contact between a and 11a, damage caused by movement friction, lack of reliability in proper meshing of both meshes, and excessive load carrying capacity of the jack 15 and drive cylinder 14. It is true. In other words, there is no need to bring the half nut 11 into contact with the tie rod 4 under pressure, and the load is applied only when both screw teeth 13a, 11a reach the fully engaged position. Both the drive load and the drive load of the drive cylinder 14 are smaller than conventional ones, and the jack 15 is loaded only by the weight of the half nut 11 and the plate 10, and the drive cylinder 14 presses the nut 11 at a constant rate when closed. Since only the pressure required for opening and closing is required, the equipment structure for both can be of small capacity, and the cylinder 14 can be made small and compact, and the jack 15 and drive motor 16 can be made small and compact. Thus, accurate and smooth engagement of the screw teeth 13a and 11a with high precision can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the main parts of a tuning device of an example of an injection molding machine using an embodiment of the device of the present invention, FIG. 2 is a front view of an embodiment of the detection member, and FIG. FIG. 4 is a front view of an example of the vertical injection molding machine used, FIG. 4 is a side sectional view of the main parts of the tuning device, and FIG. 5 is an operation flow diagram of an embodiment of the apparatus of the present invention. FIG. 6 is a front view showing another example of the configuration of the detection member 18, and FIG. 7 is a side view of the same. 1...Molding machine frame, 2...Bed (fixed plate), 3...Top platen, 4...Tie rod,
5...Fixed type, 6...Slide (movable plate), 7...
...Mold opening/closing cylinder, 8...Movable mold, 9...Mold clamping cylinder, 10...Half nut plate, 1
1...Half nut, 12...Cover, 11a,
13a...screw tooth, 14...drive cylinder, 15
... jack, 24 ... detection member, 25 ... control device.

Claims (1)

[Scope of Claims] 1. Consisting of a fixed mold fixed on the frame side of an injection molding machine, and a movable mold movable toward the fixed mold so as to be able to be opened and closed forward and backward and held along a tie rod belonging to the frame, A positioning half nut, which is movable in the same direction as the movable mold and also along the tie rod, is moved forward and backward in a direction orthogonal to the tie rod, and is attached to the threaded portion of the tie rod. , which removably engages the threaded portion of the half nut, comprising drive devices 15 and 16 that move the half nut 11 relative to the movable die 8, and the positioning threaded portion of the tie rod 4 and the half nut 11. Both screw teeth 13 in the threaded part of
A detection member 18 for detecting the proper meshing position of the teeth 11a and 11a is provided between both threaded portions, and when the detection member 18 detects the proper meshing position of the threaded teeth 11a and 13a, the drive device 1
1. A mold thickness adjusting device for an injection molding machine, characterized in that a control device 25 is provided for stopping parts 5 and 16.