JPH0331570B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical injection molding machine in which both a mold clamping mechanism and an injection mechanism are driven by one electric motor.

Conventionally, mechanical injection molding machines that use an electric motor as a drive source are known as plunger injection molding machines, which use the rotational force of an electric motor that rotates at a constant speed to drive gears, link mechanisms, etc. Since the operating speed and output are fixed, and the required performance is different for the mold clamping mechanism and the injection mechanism, separate electric motors are installed to drive each. The equipment was complicated, and its performance and operability as an injection molding machine were unsatisfactory.

This invention enables a high-performance injection molding machine with a simple structure and good operability, in which both the mold clamping mechanism and the injection mechanism are driven by a single machine using a servo motor or the like. It is.

Furthermore, even if the transmission shaft is provided between the mold clamping mechanism side and the injection mechanism side, the transmission shaft is moved in the axial direction so that the transmission shaft does not interfere with the nozzle touch due to movement of the injection mechanism side. The object of the present invention is to provide an injection molding machine which is slidably connected to the injection molding machine.

A mold clamping mechanism equipped with a screw shaft mechanism that converts rotational force into thrust to move the movable platen, and an injection mechanism equipped with a screw shaft mechanism that converts rotational force into thrust to move the screw in the injection heating cylinder. Both the mold clamping mechanism and the injection mechanism are provided with transmission shafts that transmit rotational force to the screw shaft mechanism, and an electric motor is connected to one of the transmission shafts, and the transmission shafts are connected to each other in the axial direction. The injection mechanism is configured to be slidably connected to the mold clamping mechanism and movable with respect to the mold clamping mechanism.

The present invention will be explained in detail below with reference to embodiments shown in the drawings.

In the figure, 1 indicates a mold clamping mechanism, and 2 indicates an injection mechanism. The mold clamping mechanism 1 includes a tie bar 12 installed on a pair of fixed plates 10 and 11 on a machine stand 3, and a movable plate 13 movably attached to the tie bar 12. Molds 14, 14 are provided on opposing surfaces of the fixed plate 11 and the movable plate 13, respectively, and the movable plate 1
On the opposite side of 3 is a screw shaft 1 that converts rotational force into thrust.
5 is protruding. This screw shaft 15 is screwed into a rotary disk 16 which is rotatably attached to the other fixed plate 10, and a gear 17 is attached to the rotary disk 16. When rotated, the screw shaft 15 moves together with the movable platen 13 by the screw lead.

The injection mechanism 2 includes an injection heating tube 21 containing a screw 20 therein, and a movable housing 22 on a machine base that also serves to hold the injection heating tube 21. Inside the housing 22, there is a rear end of the screw 20 and a pair of support shafts 24, 24 installed on both sides in parallel with the screw. A moving member 25 for transmitting information to the screw is mounted so as to be slidable in the front-back direction.

Further, a rotating shaft 27 having a screw rotation gear 26 is connected to the rear end of the screw 20, and an end of the rotating shaft 27 is attached to the screw moving member 25.
It is rotatably connected to.

Furthermore, a screw shaft 30 is screwed into the screw receiving member 28 provided at the rear of the screw moving member 25, which is rotatably held on the housing wall 22a and is integral with a shaft portion 30a having an injection gear 29. In addition, the outer end of the shaft portion 30a is connected to the housing wall portion 2.
It is connected to a brake device 31 fixed to 2a. This brake device 31 is equipped with a hysteresis brake inside.

Reference numeral 32 denotes a transmission shaft on the mold clamping mechanism side, which is rotatably supported under the fixed plates 10 and 11 and has a transmission gear 55 at its outer end that is close to the fixed plate 10 and meshes with the gear 17. A key or spline 32a is provided at the inner end.

Reference numerals 33 and 34 denote transmission shafts on the injection mechanism side, which are supported in parallel in the lower part of the housing 22, and the transmission shafts 33 and 34 are connected to the transmission gears 3 attached to the respective transmission shafts.
5 and 36 are engaged so that they rotate simultaneously.

Further, a drive belt 38 is provided to extend between the outer end of the transmission shaft 34 and a servo motor 37 installed on the lower side of the housing, and the servo motor 37 rotates both the transmission shafts 33 and 34. Note that 39 is a belt wheel.

A connection shaft 40 for connecting the transmission shaft 32 on the mold clamping mechanism side is connected to the inner end of the transmission shaft 33 via an electromagnetically actuated clutch mechanism 41 so as to be movable towards and away from it.

The connection shaft 40 includes a shaft portion 40a rotatably supported by the housing 22, and a keyway or spline formed integrally with the outer end of the shaft portion 40a to receive the inner end of the transmission shaft 32. It consists of a cylindrical connecting end 40b, and a shaft part 40a.
An electromagnetic brake device 42 is provided in which the transmission shaft 32 can be fixed by being combined with the housing 22.

Further, at the inner end of the transmission shaft 34, a nozzle touch member 43 for connecting the fixed platen 11 on the mold clamping mechanism side and the housing 22 is rotatably supported by the housing 22.

This nozzle touch member 43 has a shaft portion 43a,
It consists of a screw shaft 43b that is screwed into the screw receiving member 11a attached to the fixed platen 11, and an electromagnetically operated crack mechanism 44 is provided between the shaft portion 43a and the end of the transmission shaft to connect the transmission shaft 34 and the nozzle touch member 43. It is connected so that it can be freely connected and detached.

In addition, 41a and 44a in the figure are clutch plates,
Reference numerals 41b and 44b denote clutch excitation members, and 45 a transmission gear provided on the transmission shaft 33 together with an electromagnetically actuated clutch mechanism 46, which meshes with the injection gear 29.

A transmission gear 48 is provided on the transmission shaft 34 together with an electromagnetically actuated clutch mechanism 47, and is meshed with the screw rotation gear 26.

49 is a sensor for confirming the forward movement of the injection mechanism 2; 50
denotes a backward movement completion sensor, and these sensors are arranged at the position of the connection shaft 40.

Next, the injection molding process will be explained.

The clutch mechanism 41 shown in FIG.
With 2 and 33 connected, the servo motor 37
rotate in the forward direction. At this time, on the injection mechanism 2 side, the transmission gear 4 is opened by the opening operation of the clutch mechanisms 46 and 47.
Leave 5,48 in a free state. Also, the transmission shaft 34
and the nozzle touch member 43.
4 is also opened and the connection between the two is cut off. On the mold clamping mechanism side, the rotary disk 16 is rotated by the transmission shaft 32, the transmission gear 55, and the gear 17, and the screw shaft 15
is sent out. As a result, the movable platen 13 moves forward to close the molds 14, 14, and further strong mold clamping is performed. When the mold clamping pressure reaches the predetermined pressure, the connection shaft 4
The electromagnetic brake 42 at position 0 is operated to fix the transmission shaft 32 to the housing side, and the clutch mechanism 41 is further opened to disconnect the transmission shaft 33.
Continuing with this operation, the clutch mechanism 44 closes on the injection mechanism side, and the transmission shaft 34 and the nozzle touch member 43 are connected and rotated at the same time. This rotation causes the screw shaft 43b to enter into the fixed platen and pull the housing 22. At this time, the transmission shaft 3
2 is connected to the transmission shaft 33 through the connection shaft 40 so as to be slidable in the axial direction, so the housing 22 moves on the machine base in the direction of the fixed part 11 regardless of the transmission shaft 33, and the nozzle touch there. occurs.

When the nozzle touch is confirmed by the forward movement confirmation sensor 49, the electromagnetic brake 51 fixes the nozzle touch member 43 to the housing side, opens the clutch mechanism 44, disconnects it from the transmission shaft 34, and closes the clutch mechanism 46. It operates to connect the transmission shaft 33 and the transmission gear 45, and the injection gear 2
9 is rotated together with the screw shaft 30. This screw shaft 30
The screw moving member 25 moves forward due to the rotation of
Injection is performed by extruding the screw 20.

When the injection is completed, the servo motor 37 stops, and at the same time the clutch mechanism 46 is opened to free the transmission gear 15 relative to the transmission shaft 33.
Further, a clutch mechanism 47 is operated to close the transmission shaft 34 to connect the transmission shaft 34 and the transmission gear 48.

When the servo motor 37 is driven, the screw rotation gear 26 is rotated by the transmission gear 48, the screw 20 is also rotated together, and charging of the material is started. At this time, the brake device 31 is applied to generate screw back pressure. The material from the hopper is melted and forced to the tip of the screw by the rotation of the screw 20, and the pressure at that time
0 retreats together with the screw moving member 25. When this retracted position is electrically confirmed and material charging is completed, the servo motor 37 is stopped and the clutch mechanism 47 is opened to disconnect the transmission shaft 34.
Once the resin injected and filled into the molds 14, 14 has cooled down, the electromagnetic brake 42 is deactivated, and then the electromagnetic brake 51 is released, and the clutch mechanism 44 is closed to reduce the transmission. axis 34
When the servo motor 37 is rotated in the opposite direction after connecting the nozzle touch member 43, the screw shaft 43b is also rotated in the opposite direction, pushing the housing back in its original direction. As a result, the nozzle touch is released, and this confirmation is performed by the above-mentioned retraction completion sensor 50.

After that, the clutch mechanism 41 is operated to close, and both the transmission shafts 33 and 32 are connected again, and the servo motor 37
is rotated in the opposite direction to open the mold, and the molded product is taken out, completing one cycle of injection molding. Of course, depending on the mold, molding may be carried out with the nozzle in the touch state without having to move the nozzle back in each molding cycle.

As described above, this invention uses an electric motor such as a servo motor as a power source, and also connects the transmission shaft between the injection mechanism and the mold clamping mechanism so that they can slide, and operates both mechanisms using one electric motor. Since this is made possible, the following effects are achieved.

(1) Very large torque can be obtained at low speed rotation, so there is no need to use a reduction gear.

(2) The equipment is simpler than when using hydraulics;
Expensive equipment such as hydraulic pumps and control valves is not required, the weight of the machine is significantly reduced, and it can be configured more compactly.

(3) Since no hydraulic oil is required, there is no need for temperature control, pollution control, or replacing hydraulic oil due to deterioration, and power transmission efficiency is higher than that of hydraulic systems, resulting in power savings.

(4) Since the injection mechanism side and the mold clamping mechanism side can be operated by the same electric motor, power can be saved, the equipment can be simplified, and it is highly economical.

(5) Since the injection mechanism side can be easily moved forward and backward by moving the transmission shaft in the axial direction, nozzle touch can be carried out smoothly.

[Brief explanation of drawings]

The drawings illustrate an injection molding machine according to the present invention, and FIG. 1 is a partial longitudinal sectional front view, and FIG.
3 is a sectional view taken along the line in FIG. 1, FIG. 4 is a sectional view taken along the line shown in FIG. 1. 1... Mold clamping mechanism, 2... Injection mechanism, 10, 11
... Fixed plate, 20 ... Screw, 22 ... Housing, 26 ... Screw rotation gear, 29 ... Injection gear, 32, 33, 34 ... Transmission shaft, 32a
... Spline, 40 ... Connection shaft, 40a ... Shaft portion, 40b ... Connection end.

Claims (1)

[Claims] 1. A mold clamping mechanism equipped with a screw shaft mechanism that converts rotational force into thrust to move the movable platen, and an injection mechanism equipped with a screw shaft mechanism that converts rotational force into thrust and moves the screw in the injection heating cylinder. Both the mold clamping mechanism and the injection mechanism are individually provided with transmission shafts that transmit rotational force to the screw shaft mechanism, and an electric motor is connected to one of the transmission shafts, and the transmission shafts are connected to each other. An injection molding machine characterized in that an injection mechanism is configured to be movable with respect to a mold clamping mechanism by being slidably connected in a direction.