JPH07119008B2 - Lifting prevention device for injection unit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a front portion of an injection unit in an injection molding machine from floating when a nozzle is touched.

2. Description of the Related Art As shown in FIG. 2, an injection unit d of a type having wheels a and moving back and forth on a rail c provided on a base b of an injection molding machine main body is fixed to a lower portion of an extruder base e. , L-shaped bending pieces f, which are bent outward in cross section, on the lower surface of the rail c in the main body base b,
The lateral surface portion h is engaged to prevent rising.

However, since this prevention structure is a structure in which the lateral surface portion h of the engagement piece f engages with the rail c from below, it is not possible to completely prevent the injection unit from rising.

That is, since the rail c is processed after fixing the material on the base b of the main body by means such as welding, even if the upper surface side on which the wheel a runs can be processed relatively accurately, the engaging piece The lower surface side with which f is engaged can hardly be processed, and the surface roughness of the material, the warp or the depression of the material may remain as it is, and the engaging piece f travels smoothly along such a surface. Due to the design, the lower surface of the rail c and the engaging piece f
A clearance of about 0.1 to 0.5 mm is required between the side surface h of the injection unit d and the front part of the injection unit d is slightly lifted due to the force of drawing the injection unit when the nozzle is touched due to this clearance. Has occurred.

Since the lift at the front of the extruder base e is enlarged at the nozzle at the front end of the cylinder assembly that extends long forward, if the above lift occurs, appropriate nozzle touch may not be performed depending on the case and resin leakage etc. may occur. It will be a hindrance. This is even more so in precision molding where more accurate nozzle touch is required.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention, in an injection unit equipped with an extruder base of a type that moves back and forth on a rail via wheels, suppresses the lift in a nozzle touch state to 0 to 0.1 mm or less. It is an object of the present invention to provide a floating prevention device that can be used.

Means for Solving the Problem In an injection unit that is equipped with wheels on an extruder base and moves back and forth on a rail fixed to the upper surface of the base of an injection molding machine body, shoulders on both sides along the moving direction of the extruder base. The floating prevention plate fixed to the main body base side is slidably engaged with the shoulder portion from above.

Action The rails provided on the main body of the injection molding machine and the floating prevention plate regulate the vertical position of the extruder base in the injection unit.

The shoulders on the extruder base allow the anti-floating plate to engage this base from above.

Embodiment In FIG. 3, an injection molding machine 1 is provided with a mold clamping unit 3 and an injection unit 4 on a main body base 2 thereof. In the drawing, the injection unit 4 is drawn to the mold clamping unit side by a nozzle touch device 5, and injection is performed. The nozzle touch state is shown in which the nozzle at the tip of the cylinder 6 is pressed by the mold attached to the fixed platen of the mold clamping unit 3.

The mold clamping unit 3 is for precision machining, but its structure has no particular relation to the gist of the present invention, and therefore its explanation is omitted.

The injection unit 4 includes an extruder base 8 having wheels 7 on the front, rear, left and right, and a mechanism section 9 including a measuring mechanism, an injection mechanism, and a driving mechanism for these, in addition to the cylinder assembly 6 described above. The rail 10 fixed on the main body base 2 of the molding machine 1 can be moved back and forth via the wheels 7.

As shown in FIG. 1, the extruder base 8 has shoulders 11 on both sides in the moving direction, and a floating prevention plate 12 is fixed to the main body base 2.

The lifting prevention plate 12 is a long member having a vertical surface portion 13 whose lower edge is fixed to the main body base 2 and which rises above the base 2 and a lateral surface portion 14 which extends inward from the upper edge thereof.
The rear surface of the lateral surface portion 14 is engaged with the shoulder portion 11 of the extruder base 8 from above.
The part where both are engaged is precisely processed, and the vertical dimension is controlled in micron units. In addition, a solid lubricant 15 such as an oilless metal is used at the contact point.

Similarly, the rail 10 and the wheel 7 are also precision-machined, and the guide ridge 16 is formed on the inner edge of the upper surface of the rail 10.

The injection unit 4 which has been retracted due to purging or replacement of the cylinder assembly 6 is advanced on the rail by the nozzle touch device 5 during the injection molding process to be in a nozzle touch state. In this state, the attracting force of the nozzle touch device 5 causes the extruder base 8 to float forward around the rear wheel. This action engages the shoulder portion 11 of the extruder base 8 from above. The extruder base 8 is not lifted by being received by the lateral surface portion 14 of the floating prevention plate 12. Further, the forward / backward movement of the extruder base 8 is accurately and smoothly performed by the engagement of the shoulder portion 11 and the floating prevention plate 12.

In the first embodiment, the vertical surface portion 13 and the horizontal surface portion 14 of the long floating prevention plate 12 are configured to close the shoulders 11 and below of the extruder base 8, which are similar to the cover. Since it performs the function of, the shoulder 11 and the wheel 7 that have been precision processed
Also, foreign matter is prevented from entering the portion of the upper surface of the rail 10 from the outside, and this portion is protected. However, in the present invention, the floating prevention plate 12 may be configured to be able to engage with the shoulder portion 11 of the extruder base 8 from above, and may not necessarily include the vertical surface portion 13 and the horizontal surface portion 14. Further, it may be provided only at the front and rear positions on both sides of the extruder base 8 instead of the long material.

FIG. 4 shows the second embodiment. The wheel 7 in the first embodiment is a roller follower 17 in which a roller shaft fixed to the side surface of the extruder base 8 is mounted via a ball bearing, and the roller is a roller. The inner surface of the follower 17 is engaged with the guide projection 16 of the rail 10, and the inner surface of the vertical surface portion 13 of the lift preventing plate 12 is brought into contact with the outer surface of the roller follower 17.

According to the structure of the second embodiment, the guide protrusion 16 of the rail 10 and the vertical surface portion 13 of the floating prevention plate 12 also regulate the lateral deviation of the roller follower 17, so that the nozzle touch can be performed more accurately.

EFFECTS OF THE INVENTION Since the shoulder portion provided on the extruder base and the contact portion of the floating prevention device can be precisely machined, the clearance at this contact portion can be made extremely small, and the floating of the injection unit at the time of touching the nozzle is almost eliminated. It can be resolved.

Since it is not necessary to set a clearance for irregular unevenness or warpage, it is easy to manage the height of the floating prevention device.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an essential part, FIG. 2 is a longitudinal sectional view showing an essential part of a conventional example, FIG. 3 is a front view showing an outline of an injection molding machine, and FIG. 4 is a second embodiment. Sectional drawing of the principal part which shows. 1 ... Injection molding machine, 2 ... Main body base, 3 ... Mold clamping unit,
4 ... Injection unit, 5 ... Nozzle touch device, 6 ... Cylinder assembly, 7 ... Wheel, 8 ... Extruder base, 9 ... Mechanism part, 10 ... Rail, 11 ... Shoulder part, 12 ... Lifting prevention plate, 13 ... Vertical Face part, 14 ... Lateral part, 15 ... Solid surface material,
16 ... Guide ridge, 17 ... Roller follower.

Claims (3)

[Claims] 1. An injection unit which is provided with wheels on an extruder base and which moves back and forth on a rail fixed to the upper surface of the base of an injection molding machine body, wherein shoulders are provided on both sides of the extruder base along the moving direction thereof. An uplift prevention device for an injection unit, wherein an uplift prevention plate fixed to the body base side is slidably engaged with the shoulder portion from above. 2. An elongate member having a vertical surface portion in which a floating prevention plate is fixed and raised to the main body base side and a horizontal surface portion extending inward from an upper edge thereof. The rising prevention device for an injection unit according to claim 1, wherein a back surface is slidably engaged with the shoulder portion from above. 3. The rail is provided with guide ridges on its inner edge for contacting the inner surface of the wheel of the extruder base, and the vertical inner surface of the floating prevention plate is in contact with the outer surface of the wheel. A floating prevention device for an injection unit according to the second aspect.