JPH0727147Y2 - Half-nut rust preventive device for injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a rust preventive device applied to a half nut of an injection molding machine.

(Prior Art) FIG. 2 shows a conventional mold clamping device, in which 150 is a base on which the mold clamping device is mounted and fixed, and a fixed die plate 154 for mounting a fixed mold 152 at one end of the base 150. Is fixed. 158 is a movable die plate, a movable die 156 is attached to the fixed die plate 154 side, a slide shoe 159 is integrally attached to the leg of the movable die plate, and a guide provided on the base 150. It is mounted so that it can move forward and backward along the rail 151.

Further, hydraulic cylinders 160 for generating a mold clamping force after mold closing are formed at four corners of the fixed die plate 154. The hydraulic cylinders 160 sandwich a ram 162 and have oil chambers 161A and 161B inside.
Is provided. As shown in the enlarged view of FIG. 3, the ram 162 has a multi-step outer circumference with large, medium, and small diameters, and an insertion hole 174 for the tie bar 164 is formed through the shaft center. By sending pressure oil to the oil chamber 161A, the ram 162
2 moves to the right in FIG. 2, the tip portion 163 of the half nut 180 is brought into contact with the half nut 180, and
The half nut 180 is pushed further to the right in the state of meshing with the 4 to generate the mold clamping force. One end of the tie bar 164 is fixed to the moving die plate 158 by a nut 165, and a threaded portion 172 is formed at a tip of the tie bar 164 over a predetermined length. The threaded portion 172 is the fixed die plate 1 at the time of mold clamping.
It is designed to mesh with a half nut 180 provided on the back side of 54.

Reference numeral 166 denotes a die opening / closing cylinder attached to the fixed die plate 154 or the moving die plate 158, which moves the moving die plate 158 forward and backward. The tip of the rod 170 of the die opening / closing cylinder 166 is the moving die plate 158 or the fixed die plate. It is fixed to the die plate 154. 175 and 176 are fixed die plates
A packing presser fixed to the front and rear of the part of the mold clamping cylinder 154 is used to fix a guide bar 177 that supports a half nut 180 so that it can move forward and backward. Has been done. A half nut 180, which is a nut divided into two and is opposed to the guide bar 177, is slidably supported via a bracket 178. The half nut 180 is constantly rammed by a spring 179.
The tip portion 163 of the 162 is urged to come into pressure contact. At the same time, the end surface 163a of the ram 162 is also pressed against the stopper surface of the sprocket 190.

The screw rod 191 attached to the packing retainer 176 engages with the sprocket 190 whose inner surface is threaded,
The sprocket 190 is moved to the third position via the chain 195 by a chain drive device such as a stepping motor (not shown).
It moves back and forth in the direction indicated by the arrow in the figure. That is, half nut
By adjusting the position of 180, the meshing position of the screw thread can be adjusted.

Furthermore, in order to prevent dust from entering the half nut 180 and accidents such as pinching your hand, the half nut cover 20
0 is fixed to the packing retainer 176. Further, the half nut cover 200 is formed with an opening 200b through which the chain 195 passes.

(Problems to be solved by the invention) When a corrosive resin such as hard vinyl chloride is molded, a corrosive gas (Hcl in the case of PVC) is generated from a nozzle, a parting surface of a mold, a gas vent hole and a hopper (not shown). . The material of hard vinyl chloride is powdery, and the plasticizers such as dioctyl phthalate and dioctyl phthalate are also corrosive and rust or peel off the paint.

The following measures can be considered as measures to deal with the above. That is, the half nut 180 and the tie bar 164 may be plated with chrome, or a grease lubrication device may be used to constantly spray grease, but these are not sufficient because of the following drawbacks.

That is, there is a fear that the surface of the chrome plating may be peeled off due to a high surface pressure applied to the threads, or that the meshing of the chrome plating may cause a seizure problem. In addition, not only is it difficult to collect the grease by constantly applying grease, but the half nut cover 200 cannot be completely sealed.
When moving by 58, there was a problem that the grease attached to the tie bar 164 drips into the mold and stains the molded product.

The present invention has been proposed to solve the above conventional problems.

(Means for Solving the Problem) For this reason, the present invention makes a fixed die plate for holding a fixed die, a movable die plate for holding a movable die, and a reciprocating operation of the movable die plate with respect to the fixed die plate. Means, a tie bar for performing mold clamping after the movable die plate approaches the fixed die plate and the fixed die and the movable die are closed, and fixed and fixed to the fixed die plate or the movable die plate; and the fixed die. In a mold clamping device, in which a half nut that can be opened and closed at substantially right angles to the tie bar axis is provided on the side of the plate or movable die plate opposite to the mold mounting surface, a cover that covers the half nut and air is supplied into the cover. It has an air supply means and the pressure inside the cover is higher than atmospheric pressure to prevent corrosive gas and dust from entering the half nut. Which is a means for solving the problems.

(Operation) Since air is supplied to the inside of the half nut cover and the pressure is higher than the atmospheric pressure, the air is constantly blown out from the opening. Therefore, it is possible to prevent corrosive gas or corrosive dust such as vinyl chloride powder from entering the half nut, so that the half nut portion can be rust-proofed.

(Embodiment) The present invention will be described below with reference to the embodiments of the drawings. FIG. 1 shows a first embodiment of the present invention. Since members 150 to 200 in FIG. 1 are the same as those described in FIG. 2, only the mechanism added to FIG. 2 will be described here.

Now, in FIG. 1, the half nut cover 200 is provided with an air blowing port 200a. Further, 201 is a tie bar cover that covers the threaded portion of the tie bar 164, 202 is an air pressure source, 203 is an air filter, 204 is a pressure control valve that controls the air supply pressure, 205 is a pressure gauge, and 206 is an air blow port of the half nut cover 200. It is an air pipe connected to 200a. The air supply means 202 to 205 are separately installed or attached to the rear portion of the moving die plate 158 where corrosive gas does not remain.

Next, the operation will be described. When pressurized air is supplied from the air pressure source 202, the air filter 203 filters contaminants such as dust in the air. The operator adjusts the pressure control valve 204 while watching the pressure gauge 205 to set the pressure to 4 to 5 kgf / cm ² . Then, the air pressurized to this pressure is supplied from the air blowing port 200a of the half nut cover 200.

Opening 2 of the half nut cover 200 with pressurized air
00b, the air gap between the half nut cover 200 and the packing presser 176, the air gap between the tie bar cover 201 and the packing presser 175, and the gap between the tie bar 164 and the left end opening of the tie bar cover 201. It will be discharged. Therefore, corrosive gas and corrosive dust are not mixed in the half nut part and the screw part of the tie bar.
Can prevent rust. As an embodiment of the present invention, in FIG. 1, the half nut is described as a mold clamping device on the side of the fixed die plate 154 opposite to the die mounting surface. It is also applicable to the mold clamping device on the side.

(Effect of the Invention) Since the present invention is configured as described in detail above,
Effective rustproofing can be performed even on tie bars such as chrome plating, which are difficult to surface-treat, and screw parts of half nuts. In the past, a completely sealed structure was required to prevent the ingress of corrosive gas and corrosive dust, but in the present invention, air of a pressure larger than atmospheric pressure is supplied to the cover, Even if there is an opening, invasion of gas, dust, etc. can be prevented. Therefore, the structure of the cover that covers the half nut can be simplified, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front sectional view of a half nut rust preventive device according to an embodiment of the present invention, FIG. 2 is a front sectional view showing an example of a conventional mold clamping device, and FIG. 3 is a main part of FIG. It is a detailed sectional view. Description of main parts of the figure 200 …… Half nut cover 200a …… Air inlet 201 …… Tie bar cover 202 …… Air pressure source 203 …… Air filter 204 …… Pressure control valve 205 …… Pressure gauge 206 …… Air piping

Claims (1)

[Scope of utility model registration request] 1. A fixed die plate for holding a fixed mold,
A moving die plate for holding the moving die, a means for moving the moving die plate backward with respect to the fixed die plate, and the moving die plate approaching the fixed die plate to close the fixed die and the moving die. After that, a tie bar that is fixedly coupled to a fixed die plate or a movable die plate to perform mold clamping, and a half nut that can be opened and closed on the side opposite to the die mounting surface of the fixed die plate or the movable die plate approximately at right angles to the axis of the tie bar. In the mold clamping device provided with, a cover for covering the half nut and an air supply means for supplying air to the cover are provided, and by setting the pressure inside the cover to be greater than atmospheric pressure, corrosive gas and dust Half-nut rust preventive device for injection molding machines, which prevents the intrusion of the half-nut into the half nut.