JPH08281733A - Metering unit for injection molding machine - Google Patents

Abstract

PURPOSE: To provide a metering unit for an injection molding machine which need not to use a large-sized thrust bearing by easily controlling the backward movement and the stop of a screw and by alleviating the load when an overload is applied to a load cell in the metering unit for metering a molding material by the backward movement and the stop of the screw while rotating the screw. CONSTITUTION: A thrust bearing 78 and a spacer 77 are interposed between a load cell 76 contained in the housing 73a of a carriage 73 for pushing a screw shaft 90 and the flange 65a of the end of a screw drive shaft 65 at the time of injection. A clutch and brake means are provided at the second output shaft for forming the drive system of the carriage 73, the clutch is disengaged at the time of metering. When the detected value of the cell 76 is smaller than a threshold value, the brake means is operated to stop the backward movement of the shaft 90, while when it is larger than the threshold value, it is released to allow the backward movement. At the time of an overload, the overload of the flange 65a to the cell 76 as suitable deflection shape and size is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device for measuring a molding material to be injected, mainly in a screw type injection device of an injection molding machine.

[0002]

2. Description of the Related Art An injection device of an injection molding machine is a device for injecting a molten molding material into a mold, and it is a meter for adjusting a predetermined injection amount of the molding material to be injected prior to injection. Is performed. Further, in the measuring step, kneading and plasticization of the molding material are simultaneously performed. That is, when the molding material is supplied from the hopper into the heating cylinder, the molding material is pushed to the tip of the cylinder while being kneaded by the rotation of the screw. At this time, the molding material is heated by the heater on the outer circumference of the heating cylinder and melts while being kneaded. As the molten material is accumulated at the tip of the heating cylinder, the screw is pushed back by receiving the back pressure and retracted. If the amount of retreat is detected by a sensor and the rotation of the screw is stopped, a predetermined amount of molding material is supplied.

A load cell is generally used to measure the back pressure. When the back pressure applied to the load cell is smaller than a predetermined value (threshold value), the screw is prevented from retreating and a molding material is used. The drive mechanism for injection is controlled so that only the supply of When the back pressure becomes larger than the threshold value, the drive mechanism for injection is controlled so as to allow the screw to retract.

[0004]

However, the above-mentioned conventional injection molding machine has the following problems because the injection mechanism and the measuring mechanism are provided with drive mechanisms such as electric motors, respectively.

The drive mechanism for the injection mechanism is a mechanism for advancing the screw in order to inject the molding material into the mold from the nozzle. However, since the screw retracts during the metering operation, the mechanism for allowing this retraction is constructed. Must. Further, as described above, it is necessary to control so as to prevent this backward movement during the measurement. That is,
During the weighing operation, it is necessary to control two mechanisms, that is, a driving mechanism for the weighing mechanism and a driving mechanism for the injection mechanism, and when each mechanism is provided with an electric motor as in the conventional case. It is necessary to control each of these electric motors, and the control mechanism for weighing is complicated. When the back pressure is small, the electric motor for the injection mechanism is driven to advance the screw as needed.

Further, in the conventional mechanism, if a back pressure that causes an overload is applied to the load cell, the load cell may be damaged. Therefore, the thrust bearing interposed between the load cell and the flange portion is used as a load bearing. The load cell is made large so that it is not overloaded. Therefore, a large thrust bearing is used, the portion holding the load cell becomes large, the weight becomes large, and the entire injection device becomes large.

Therefore, the present invention makes it possible to easily control the forward / backward movement of the screw during the metering operation, and relaxes the load applied to the load cell by the back pressure without using a large thrust bearing. It is an object of the present invention to provide a weighing device for an injection molding machine which can be manufactured without damaging a load cell.

[0008]

As a technical means for achieving the above object, a measuring device of an injection molding machine according to the present invention detects a back pressure applied to an injection mechanism member when measuring a molten material. In a measuring device of an injection molding machine for measuring the molten material while controlling the retreat of the injection mechanism member, a load cell for receiving the back pressure via a flange portion is provided, and between the flange portion and the load cell, A bearing for receiving the rotation of the flange is interposed, the injection mechanism member is advanced from the load cell through the flange during injection, and when a load of a predetermined magnitude is applied, the flange is The feature is that it bends appropriately.

Further, in order to easily control the metering operation, the molten material is pushed to the nozzle portion by the rotation of the screw rotatably provided in the heating cylinder,
A screw-type injection molding machine equipped with an injection device that detects the back pressure applied to the screw and controls the backward movement of the screw to measure the molten material, and then advances the screw to perform the injection operation after the measurement. In the metering device, the braking means is provided in the middle of the power transmission path for advancing and retracting the screw, the transmission path of the advancing / retreating power is cut during the rotation operation of the screw, and the back pressure applied to the screw at the time of weighing is applied to the braking means. It is characterized by controlling by the operation and non-operation of.

Further, in order to simplify the control during the metering operation and downsize the back pressure detecting portion, the molten material is pushed to the nozzle portion by the rotation of the screw rotatably provided in the heating cylinder, A screw-type injection molding machine equipped with an injection device that detects the back pressure applied to the screw and controls the backward movement of the screw to measure the molten material, and then advances the screw to perform the injection operation after the measurement. In the metering device described above, a load cell that receives the back pressure via a flange portion is provided, a bearing that receives rotation of the flange portion is interposed between the flange portion and the load cell, and a power for moving the screw forward and backward is provided. A braking means is provided in the middle of the transmission path, the transmission path of the forward / backward power is cut during the rotation operation of the screw, and is added to the screw during measurement. The pressure is controlled by the operation and non-operation of the braking means, the screw is advanced from the load cell through the flange portion at the time of injection, and the flange portion is appropriately changed when a load of a predetermined magnitude is applied. It is characterized by bending to.

[0011]

In the measuring step, when the molding material is supplied from the hopper or the like, the screw rotates and pushes the supplied molding material to the tip of the heating cylinder while kneading. At this time, the power transmission system of the drive mechanism for advancing and retracting the screw for the injection process is cut off so that the influence of the advancing and retracting operation of the screw is not transmitted to the drive unit such as the electric motor. When an appropriate amount is fed, the screw retracts under the back pressure from the molding material accumulated at the tip portion, and the load cell detects the reaction force due to the back pressure. When the magnitude of this reaction force is smaller than the threshold value, the braking means is operated to stop the backward movement of the screw. Since the screw continues to rotate during this time, the molding material supplied from the hopper is pushed to the tip of the heating cylinder. When an appropriate amount is stored, the back pressure becomes large and the load cell detects a reaction force larger than the threshold value. Therefore, the braking means is deactivated to allow the screw to retract. When the screw retreats to an appropriate position, the reaction force due to the back pressure becomes small, so the braking means is operated again to stop the retreat of the screw. When the screw retreats to a predetermined position while repeatedly retracting and stopping, it means that a predetermined amount of molding material has been accumulated at the tip of the heating cylinder, and the position of this screw is detected by a sensor or the like to end the measuring process. .

When the reaction force applied to the load cell becomes larger than a predetermined value, the force is received by the flange portion, and the flange portion appropriately bends to absorb the load, so that the load cell is excessively loaded. Will not be added.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The metering device for an injection molding machine according to the present invention will be specifically described below based on the illustrated embodiments. In this embodiment, an injection molding machine suitable for mounting this measuring device is described.

8 and 9 are schematic perspective views of this injection molding machine, in which the mold clamping direction is substantially vertical and the axial direction of the injection screw is horizontal so as to be substantially orthogonal to the axis of the mold clamping direction. FIG. 10 is a front view of this injection molding machine, and is shown in a partially cut cross section. A base 1 is fixed to a floor surface to be installed, four columns 3 are fixed to the base 1, and a mold clamping device 30 is provided at the center of the column 3. And
A fixed-type mounting plate 32 is fixed to the upper end of the column 3.

The lower end of the support column 3 is reduced in diameter so as to penetrate the base 1, and the upper end thereof is reduced in diameter so that the fixed-type mounting plate 32 is formed.
Through which a male screw portion is formed at the reduced diameter upper and lower ends, and a lock nut is screwed onto the male screw portion and tightened to connect the base 1 and the fixed mounting plate 32. It is connected. In addition, on the outer side of the support column 3, FIG.
As shown in FIGS. 9, 12, and 13, a strut plate 4 having a substantially U-shaped cross section so as to cover the strut 3 is used to secure the tightening force of the lock nut by the base 1 and the fixed-type mounting plate 32. It is provided in a state of receiving and holding it. Then, a reinforcing plate 4a is fixed to an intermediate portion of each of the supporting plates 4, and adjacent supporting plates 4 are connected by the reinforcing plate 4a. That is, the support plate 4 and the reinforcing plate 4a are assembled into a substantially H shape.

Further, a part of the base 1 projects laterally, and the drive portion 10 is arranged in the projecting part. This drive
10 is a power branch device 14 on the output shaft of the electric motor 12 which is the main drive source.
The input shaft of is joined together. As shown in FIGS. 2 to 4, the power split device 14 is provided with at least two output shafts 14a and 14b and can output a desired amount of power from each output shaft. is there. A small motor 16 is attached to the power branch device 14, and the output of the power branch device 14 is controlled by the small motor 16. Further, reference numeral 18 in the figure is a flywheel. The output shaft 14a projects toward the mold clamping device 30, and the output shaft 14b projects upward. A pair of pulleys 20a and 20b are fitted on the output shaft 14b, and the pulley 22a and the pulley 22a are connected via the belts 21a and 21b respectively.
Power is transmitted to the output shafts 24a and 24b, which are connected to the pulleys a and 22b and to which the pulleys 22a and 22b are fitted, by appropriately shifting the speed.

The output shafts 24a and 24b are, as shown in FIG. 11, provided with clutches 25a and 25b and a pair of universal joints 26a and 26b on the way.
Is provided so as to extend slightly above the upper end portion of the column 3. Further, as shown in FIG. 3, the output shaft 24b is provided with a braking means 27 as a braking means to stop the rotation of the output shaft 24b. The upper ends of the output shafts 24a and 24b are fixed type mounting plates as described later.
The transmission gears 29a and 29b, which are bevel gears, are fitted to the upper end of the bearing plate 28 while being supported by the bearing plate 28 provided on the 32.

As shown in FIGS. 6 and 7, the weighing transmission gear 29a fitted to the first output shaft 24a is meshed with the weighing input gear 51 which is a bevel gear for driving the weighing mechanism. There is. The weighing input gear 51 is fitted on a shaft 51a, and the shaft 51a is rotatably supported by a bearing flange portion 60a formed on one end of the support block 60.
A metering drive pulley 52 is fitted on 51a. That is, the rotation of the first output shaft 24a is transmitted from the metering transmission gear 29a to the metering input gear 51 to change the direction of the rotating shaft and rotate the metering drive pulley 52.

Further, as shown in FIGS. 6 and 7, the injection transmission gear 29b fitted to the second output shaft 24b is meshed with the injection input gear 71 composed of a bevel gear for driving the injection mechanism. There is. The injection input gear 71 is fitted to one end of a shaft 71a, and the shaft 71a is rotatably supported by a bearing flange portion 60b formed at the other end of the support block 60. Injection drive gear consisting of a bevel gear at the other end
72 is fitted. That is, the rotation of the second output shaft 24b is transmitted from the injection transmission gear 29b to the injection input gear 71 to change the direction of the rotation shaft and rotate the injection drive gear 72.

The shaft 51a is supported by a bearing bracket 28a provided on the bearing plate 28 as shown in FIG. 5, and the shaft 71a is supported by the bearing plate 28a as shown in FIGS. 5 and 14 to 21. It is rotatably supported by a bearing bracket 28b provided on the. The shaft 51a and the shaft 71a are arranged on the same straight line. Therefore, the support block 60 supporting the shafts 51a and 71a is swingably supported around the shafts 51a and 71a.

As shown in FIGS. 6 and 7, a pedestal plate 61 extends in the direction opposite to the fixed type mounting plate 32 at the lower center of the support block 60. Block 62 is fixed. A bearing block 63 is rotatably supported at the center of the support block 62, and the bearing block 63 has a screw drive gear formed of a bevel gear.
64 is provided so that the bearing block 63 and the screw drive gear 64 rotate integrally. In addition, the side portion of the support block 62 on the side of the first output shaft 24a is
As shown in 12, a bearing block 62a is attached, and a transmission gear 54 that meshes with the screw drive gear 64 is fitted to one end of a transmission shaft 53 that is rotatably supported by the bearing block 62a. There is. A transmission pulley 55 is fitted to the other end of the transmission shaft 53, and a belt 56 is stretched over the transmission pulley 55 and the measuring drive pulley 52, and the rotation of the measuring drive pulley 52 is transmitted to the belt 56. Shaft 53, transmission gear 54
It is transmitted to the screw drive gear 64 via the, and the screw drive gear 64 is rotated. As shown in FIGS. 5 and 12, the belt 56 is guided in the middle by a tensioning wheel 57 so that the belt 56 is provided with an appropriate tension so that power is transmitted between the metering drive pulley 52 and the transmission pulley 55. It is done smoothly.

On the bearing block 63, a screw drive shaft 65 whose horizontal direction is an axial direction is supported via a spline. Therefore, when the bearing block 63 rotates, the screw drive shaft 65 also rotates integrally with the bearing block 63 via the spline.
Is slidable in the axial direction. A screw shaft 90 supported by being inserted through the central portion of the support block 60 is connected to the tip of the screw drive shaft 65.
The screw shaft 90 is designed to rotate integrally with the screw drive shaft 65. FIG. 1 is a cross-sectional view showing a state in which the screw drive shaft 65 and the screw shaft 90 are connected to each other. A flange portion 65a is formed at the tip of the screw drive shaft 65, and a boss portion 65b is further formed at the tip. There is. A connecting hole 65c is formed in the center of the boss portion 65b, the base end 90a of the screw shaft 90 is inserted into the connecting hole 65c, and the connecting hole 65c and the base end 90a are connected by a key or a spline. are doing. Base end of screw shaft 90
90a has a neck 90b with a reduced diameter.
The bush 90d divided into 90b is fitted and fixed to the boss portion 65b of the screw drive shaft 65 with a screw or the like so that the screw shaft 90 does not separate from the screw drive shaft 65. Further, the flange portion 65a is set to have a size and a shape such as a wall thickness and an outer diameter so as to be appropriately bent by a reaction force due to a back pressure received from the molding material during a measuring operation.

A tip portion of the screw drive shaft 65 is inserted into a housing portion 73a formed in a central portion of a carriage 73 described later, and a cover plate 74 is fixed to the carriage 73 at a portion where the flange portion 65a is located. There is. Further, a bush 75 having a diameter smaller than the inner diameter of the housing portion 73a is fitted on the proximal end side of the screw driving shaft 65 of the housing portion 73a, and the screw driving shaft 65 is inserted into this bush 75. A load cell 76 for detecting a load is housed in the housing portion 73a, which is sandwiched between the bottom surface of the housing portion 73a and the flange portion 65a, and the screw drive shaft 65 inserts the load cell 76 therethrough. A thrust bearing 78 is interposed between the load cell 76 and the flange portion 65a via a spacer 77.

As shown in FIGS. 5 to 7 and 12, the support block 60 and the carriage 73 include a screw shaft.
A pair of drive rods 81a, 8 with the direction parallel to 90 as the axial direction
1b is passed over. Male screw portions are formed from the tip end side of the drive rods 81a and 81b to appropriate positions, and the base end portions are fixed to the end portions of the carriage 73, respectively. Further, the support block 60 includes bearing blocks 82a and 82b.
Is rotatably supported, and pulley portions 83a and 83b are formed on the side surfaces of the boss portions of the bearing blocks 82a and 82b, respectively. Further, the bearing blocks 82a, 82b are formed with female screw portions that are screwed into the male screw portions formed on the drive rods 81a, 81b, and the drive rods 81a, 81b are formed into bearing blocks 82a.
It is supported by being screwed with a and 82b. The male screw portions formed on the respective drive rods 81a and 81b are formed to have the same pitch, and a belt 83c is stretched between the pulley portions 83a and 83b so that a rotational force is generated between them. Transmission of the pulleys 83a, 8
The speed ratio between 3b is set to be 1: 1. Further, the bearing block 82a is formed with a carriage drive gear portion 84 formed of a bevel gear that meshes with the injection drive gear 72, and the rotation of the injection drive gear 72 rotates the bearing block 82a via the carriage drive gear portion 84. I am doing it.

As shown in FIG. 12, a screw portion 91 is provided at the tip of the screw shaft 90. The screw portion 91 is housed in the cylinder body 92a of the heating cylinder and is not shown in the cylinder body 92a. The molding material is supplied from the hopper. The tip of this cylinder body 92a is
As shown in FIG. 10, the cylinder head 92b, which extends to almost the central position of the fixed type mounting plate 32 and is located at the central position, is fixed. The axial direction of the cylinder head 92b is substantially orthogonal to the axial direction of the screw portion 91, and the nozzle 93 is attached to the lower end of the cylinder head 92b. The upper end of the cylinder head 92b is shown in FIGS.
As shown in FIG. 11, a support rod 94 is fixed, and a T-shaped joint 95 is fixed to the upper end portion of the support rod 94. The central portion of the support rod 96 along the direction orthogonal to the axial direction of the screw shaft 90 is supported by the T-joint 95 so as to be rotatable around the axial direction of the support rod 96.

On the other hand, on the upper surface of the fixed type mounting plate 32, hydraulic cylinders 97a and 97b of the support rod 96 are provided on both sides of the cylinder head 92b at substantially symmetrical positions with respect to the axis of the screw shaft 90. It is rotatably supported about a direction parallel to the axial direction. And this hydraulic cylinder 97
The tips of the a and 97b piston rods 98a and 98b are rotatably connected to the support rod 96.

14 to 21 are schematic views showing the relationship between the support structure of the bearing plate 28 and the positioning mechanism of the nozzle 93.
14 to 16 show the first embodiment, FIGS. 17 and 18 show the second embodiment, and FIGS. 19 to 21 show the third embodiment.

In the embodiment shown in FIGS. 14 to 16, the bearing plate
28 is fixed to the support block 110, and this support block 11
0 is supported on the side surface of the fixed die mounting plate 32 by a pair of fixing bolts 111. This fixing bolt 111 is a support block 1
A through hole 110a formed in 10 is inserted and screwed into a female screw portion formed on the side surface of the fixed die mounting plate 32. Fixing bolt 11
A return means 112 composed of a compression coil spring is interposed between the head of 1 and the support block 110.
The restoring force of the support block 110 is urged to slide the support block 110 in the direction in which the support block 110 is pressed against the side surface of the fixed die mounting plate 32. That is, the injection device including the support block 60, the gantry plate 61, the support block 62, the screw drive shaft 65, the screw shaft 90, the drive rods 81a and 81b carriage 73, the heating cylinder, and the like is the bearing plate 28 and the support block. The cylinder head 92b is provided on the fixed die mounting plate 32 by 110 and is supported by the hydraulic cylinders 97a and 97b.

On the other hand, guide pins 113 are provided on the side surfaces of the cylinder head 92b so as to extend along a direction intersecting the sliding direction of the support block 110. The guide pin 113 is received at a position on the upper surface of the fixed mold mounting plate 32 where the nozzle 93 is sandwiched between the fixed mold mounting plate 32 and the sprue of the fixed-side mold plate fixed to the fixed mold mounting plate 32. The positioning block 114 is provided with a guide groove 114a. Moreover, this positioning block 114
Is positioned so that when the guide pin 113 is received in the guide groove 114a, the guide pin 113 rubs against the inner wall of the guide groove 114a on the side far from the support block 110 and enters. When the nozzle 93 is joined to the sprue, the guide pin 113 is in contact with the inner wall of the guide groove 114a as shown in FIG.

In the embodiment shown in FIGS. 17 and 18, the bearing plate 28
The support block 115 to which is fixed is a through hole formed in the support block 115, as in the embodiment shown in FIGS. 14 to 16.
Fixing type mounting plate with fixing bolts 116 with 115a inserted
A return means 1 which is supported on the side surface of 32 and is composed of a compression coil spring between the head of the fixing bolt 116 and the support block 115.
The support block 116 is pressed against the fixed-type mounting plate 32 by the restoring force of 17 interposed.

On the upper surface of the fixed type mounting plate 32,
Positioning block 11 on the extension line of the cylinder body 92a
8 are provided. A guide protrusion 118a projects from a portion of the positioning block 118 facing the cylinder head 92b, and a guide portion 118b having an appropriate shape is formed at the tip of the guide protrusion 118a. On the other hand, the lower end portion of the surface of the cylinder head 92b which faces the positioning block 118 is formed as a guided portion 119 so as to be easily guided by the guide portion 118b. When the nozzle 93 is joined to the sprue, as shown in FIG.
119 is in contact with the guide portion 118b.

In the embodiment shown in FIGS. 19 to 21, the bearing plate
28 is fixed to the support block 120, and this support block 12
0 is supported on the side surface of the fixed die mounting plate 32 by a pair of fixing bolts 121. This fixing bolt 121 is a support block 1
A through hole 120a formed in 20 is inserted and screwed into a female screw portion formed on the side surface of the fixed die mounting plate 32. Fixed type mounting plate 32
And a supporting block 120, there is interposed a returning means 122 composed of a compression coil spring, and the restoring force of the returning means 122 slides the supporting block 120 in a direction in which the supporting block 120 is separated from the fixed die mounting plate 32. Energized to move.
The return means 122 may be provided in a state of being wound around the fixing bolt 121 as shown in FIGS. 19 and 20, or
As shown in FIG. 21, the support block 120 may be formed to have a recess for holding the returning means 122 so as to hold it.

A guide pin 123 is provided on the side surface of the cylinder head 92b so as to extend along a direction intersecting the sliding direction of the support block 120. In addition, the guide pin 123 is received at the position on the upper surface of the fixed mold mounting plate 32 where the nozzle 93 is sandwiched in a state of being joined to the sprue of the fixed mold plate fixed to the fixed mold mounting plate 32. Positioning block 124 having guide grooves 124a formed therein
Is provided. Moreover, this positioning block 124
Is positioned such that when the guide pin 123 is received in the guide groove 124a, the guide pin 123 rubs against the inner wall of the guide groove 124a on the side closer to the support block 120 and enters. Then, in the state where the nozzle 93 is joined to the sprue, as shown in FIG.
It is in contact with the inner wall of 124a.

Next, the structure of the mold clamping device 30 will be described with reference to FIGS. 2 and 10 to 13, and 22 to 25.

The third output shaft 14a of the power branch device 14
2 and 10, extend to the inside surrounded by the four columns 3 via a universal joint 33, and a sprocket 34 and a pulley 35 are fitted to the tip end thereof. . A bearing holding plate 36 is disposed in the lower portion of the column 3, and a bearing portion 37 fixed to the bearing holding plate 36 has an axial direction parallel to the axial direction of the third output shaft 14a. Template drive shaft
38 is rotatably supported. One end of the template driving shaft 38 is located above the pulley 35, and the pulley 38a is provided at the end.
The belt 35a is attached to the pulley 35 and the pulley 38a.
And the rotation of the third output shaft 14a is applied to the template drive shaft 38.
It is transmitted to. Also, this template drive shaft 38
A pinion gear 39 is fitted to the other end of the. In addition,
The sprocket 34 fitted to the third output shaft 14a is connected to the sprocket 40a of the braking device 40 arranged on the base 1 via a chain 40b.

On the other hand, a movable type mounting plate is attached to the four columns 3.
41 is slidably supported in the vertical direction, and a mold opening / closing rod extending downward is provided at the center of the lower part of the movable mold mounting plate 41.
42 is fixed. A rack portion 42a is formed on one surface of the mold opening / closing rod 42 in the axial direction of the mold opening / closing rod 42, and the rack portion 42a is screwed to the pinion gear 39. Therefore, when the mold plate drive shaft 38 rotates, the movable mold mounting plate 41 is guided by the support column 3 through the pinion gear 39 and the rack portion 42a and slides up and down to move up and down.

The movable type mounting plate 41 is formed in a substantially rectangular shape with an appropriate thickness, and at its four corners, as shown in FIG.
The flat plate portion 41a is formed in a state of being chamfered at 45 degrees,
Bearing bracket 4 having a substantially U-shaped cross section on this flat plate portion 41a
1b is fixed at the tip of its U-shaped leg. Inside the parallel arms of this bearing bracket 41b is a movable mounting plate.
A pair of linear motion bearings 41c that guide the sliding of 41 are fixed with their bearing surfaces facing each other and in parallel with the direction of the diagonal line of the movable die mounting plate 41. On the other hand, the support surface 3 of the column 3 is formed by two flat surfaces facing the respective bearing surfaces of the pair of linear motion bearings 41c over the sliding range of the movable mounting plate 41.
A guide block 43 on which a is formed is fitted.
That is, when the movable die mounting plate 41 slides, the linear motion bearing 41c is guided by the guide surface 43a. An appropriate gap is formed between the flat plate portion 41a of the movable die mounting plate 41 and the guide bracket 43, and when the movable die mounting plate 41 expands in the diagonal direction due to heat, the expansion The amount is relaxed in this gap.

A mold thickness adjusting unit 200 is provided below the mold opening / closing rod 42. 22 to 25 are front views for explaining the mold thickness adjusting unit 200. As shown in FIGS. 22 to 25, a cylindrical nut base 201 is fixed to the upper surface of the base 1, and the upper end surface of the nut base 201 is rotatable about the shaft of the nut base 201. A thickness adjusting nut 202 is supported.
The central axis of the nut base 201 is substantially aligned with the axis of the mold opening / closing rod 42 in the vertical direction. A female screw portion is formed on the inner side surface of the mold thickness adjusting nut 202, and a gear that meshes with a worm gear described later is formed on the outer side surface.

A cylindrical mold thickness adjusting cylinder 203 is provided inside the mold thickness adjusting nut 202, and the female screw portion of the mold thickness adjusting nut 202 is screwed to the outer surface of the mold thickness adjusting cylinder 203. A matching male screw portion is formed. This mold thickness adjustment tube 203
The inner diameter of the mold is appropriately larger than the outer diameter of the mold opening / closing rod 42, so that the lower end of the mold opening / closing rod 42 can be accommodated. Further, the mold thickness adjusting cylinder 203 is prevented from rotating around the axis of the mold thickness adjusting cylinder 203 by a guide member (not shown), and is allowed to move up and down in the axial direction. That is, the mold thickness adjusting nut
When the 202 is rotated, the male screw portion screwed with the die thickness adjusting nut 202 is formed, so that the die thickness adjusting cylinder 203 is moved up and down.

The upper end portion of the mold thickness adjusting cylinder 203 is appropriately expanded in diameter to form a flange portion 203a. An appropriate number of mold clamping pistons 204 driven by hydraulic pressure are provided on the upper surface of the flange portion 203a at substantially equal intervals along an arc centered on the axis of the mold thickness adjusting cylinder 203. The piston rod of the mold clamping piston 204 slides along the lifting shaft of the mold opening / closing rod 42 by hydraulic pressure. Further, a free bearing 204a is provided on the tip surface of the piston rod to guide the smooth movement of the flat plate member placed on the tip surface in any direction.

Further, a mold closing shutter 205 is provided above the mold thickness adjusting cylinder 203. This mold closing shutter 205
As shown in FIG. 13, the planar shape is a shape in which a part of the circumference is cut out in an arc shape to form a cutout portion 205a, and a swing arm 205b is provided in a part thereof. This swing arm 20
The base end of 5b is rotatably and slidably supported by one of the columns 3, and this mold clamping shutter 205 is swingable in the horizontal plane about the column 3 and the mold opening / closing rod. 42
It is supported so that it can move up and down in the axial direction. Incidentally, the lifting and lowering of the mold closing shutter 205 is performed in synchronization with the lifting and lowering of the mold thickness adjusting cylinder 203. The tip of the piston rod of the shutter drive cylinder 206 is rotatably connected to the middle of the swing arm 205b, and the tail of the shutter drive cylinder 206 is connected to a guide bracket (not shown) fixed to the base 1. It is supported so that it can rotate and can move up and down. That is, this shutter drive cylinder 20
The operation of 6 causes the mold clamping shutter 205 to swing. Further, the bottom surface of the mold clamping shutter 205 is formed substantially flat and is placed on the universal bearing 204a, and the swing of the mold clamping shutter 205 is guided by the universal bearing 204a.

The diameter of the notch 205a formed in the mold closing shutter 205 in an arc shape is slightly larger than the inner diameter of the mold thickness adjusting cylinder 203, and when the mold closing shutter 205 swings. , As shown by the phantom line in Fig. 13, the mold thickness adjustment tube
The notch 205a is located in the inner diameter of 203 and is opened. Further, the outer diameter of the mold clamping shutter 205 is appropriately larger than the outer diameter of the circular arc in which the universal bearing 204a is arranged, and when the mold clamping shutter 205 swings, the mold clamping shutter 205 is molded. Located inside the outer diameter of the thickness adjusting cylinder 203, the inner diameter of the mold thickness adjusting cylinder 203 is closed. That is, the swing range of the mold closing shutter 205 is as shown in FIG.
It is between an open position where the inner diameter of the mold thickness adjusting cylinder 203 is opened as shown by the imaginary line above and a closed position where the inner diameter is closed as shown by the solid line in the figure.

On the other hand, a worm gear 207 meshes with the gear on the outer surface of the mold thickness adjusting nut 202. The worm gear 207 is fitted on the nut drive shaft 208, and a sprocket 209a is fitted on one end of the nut drive shaft 208. Then, the sprocket fitted to the output shaft of the nut drive motor 210 arranged at an appropriate position of the base 1.
The chain 211 is stretched over the 209b and the sprocket 209a, the output rotation of the nut drive motor 210 is transmitted to the nut drive shaft 208, and the worm gear 207 rotates.

The vertical range of the mold opening / closing rod 42 is such that the lower end of the mold opening / closing rod 42 is accommodated in the mold thickness adjusting cylinder 203 in the lowermost position and the uppermost position. It is located above the upper surface of the mold clamping shutter 205 in the opened state. That is, the fixed mold plate and the movable mold plate 41, which are mounted on the fixed mold plate 32, in this lifting range.
The mold clamping and the mold opening are performed according to the thickness of the movable side mold plate attached to the.

A projecting device 300 for projecting a molded product processed by the injection molding machine from the mold is provided below the movable mold mounting plate 41. In this embodiment, as shown in FIG. 11, the projecting device 300 includes a pair of hydraulic cylinders 3
The piston rod 01 is provided with a projecting plate 302, and an appropriate number of projecting pins 303 are provided. By the operation of the hydraulic cylinder 301, the projecting plate 302 and the projecting pin 30 are provided.
3 and up and down, so that the molded product is projected when rising.

The operation of the embodiment of the measuring apparatus of the injection molding machine according to the present invention constructed as described above will be described below with reference to FIG. 26 showing the operation sequence of the injection molding machine equipped with the measuring apparatus. To do.

A fixed side mold plate attached to the fixed mold mounting plate 32 and a movable side mold plate mounted to the movable mold mounting plate 41 by the mold thickness adjusting unit 200 according to the thickness of the mold used for molding. The height of the mold thickness adjusting cylinder 203 is adjusted so that the mold opening / closing rod 42 can be driven to a position where the mold is opened and closed properly. When the nut drive motor 210 operates, the chain 211 and the sprocket 209
The mold thickness adjusting nut 202 rotates via a, the nut drive shaft 208, and the worm gear 207. A mold thickness adjusting cylinder 203 is screwed into the inside of the mold thickness adjusting nut 202 via a threaded portion, and the mold thickness adjusting cylinder 203 is allowed to move up and down and is prevented from rotating. The rotation of the adjusting nut 202 raises and lowers the mold thickness adjusting cylinder 203. Further, when the mold thickness adjusting cylinder 203 moves up and down, the mold closing shutter 2 is synchronized with it.
05 will move up and down in synchronization, and the mold clamping shutter 2
05 is positioned higher than the upper surface of the mold thickness adjusting cylinder 203.

When the height adjustment of the mold thickness adjusting cylinder 203 is completed, in FIG. 26, the electric motor 12 of the drive unit 10 is operated to perform mold clamping at high speed (step 501). The output rotation that the electric motor 12 operates is input to the power branching device 14, the power branching device 14 is controlled, and the third output shaft 14a rotates,
The output shaft 14b remains stopped. The rotation of the third output shaft 14a is performed by the pulley 38a via the pulley 35 and the belt 35a.
Rotates, and the template drive shaft 38 rotates. Since the pinion gear 39 fitted to the mold plate drive shaft 38 meshes with the rack portion 42a formed on the mold opening / closing rod 42, the rotation of the pinion gear 39 causes the mold opening / closing rod 42 to rise. . Therefore, the mold opening / closing rod 42
The movable die mounting plate 41 fixed to the upper side rises, and the movable side die plate attached to the movable die mounting plate 41 rises at high speed until it approaches the fixed side die plate attached to the fixed die mounting plate 32. become.

When a sensor (not shown) provided on the movable die mounting plate 41 detects that the movable die mounting plate 41 approaches the fixed die mounting plate 32, the braking device 40 operates and the third output shaft is operated. The third output shaft 14a is rotated at a low speed while braking 14a to perform the mold clamping low speed (step 502). The low speed rotation of the third output shaft 14 is also transmitted to the rack portion 42a via the pulley 35, the belt 35a, the pulley 38a, the mold plate drive shaft 38, and the pinion gear 39, and the mold opening / closing rod 42 moves up at a low speed to move. Power branching device by pressing the side template to the fixed side template 14
Is controlled to stop the rotation of the third output shaft 14a. At this time, the lower end of the mold opening / closing rod 42 is attached to the mold thickness adjusting cylinder 203.
Rises above the top surface of.

Then, the mold closing shutter 205 is positioned below the mold opening / closing rod 42 to close the opening of the mold thickness adjusting cylinder 203 (step 503). That is, the shutter drive cylinder 206 operates to swing the mold clamping shutter 205 from the position shown by the imaginary line in FIG. 13 to the position shown by the solid line, and position it in the closed position. At this time, since the mold clamping shutter 205 is supported by the universal bearing 204a, the mold clamping shutter 205 smoothly swings to the closed position while being mounted on the upper surface of the mold clamping piston 204. And the mold clamping piston
204 operates to raise the mold closing shutter 205. Since the mold closing shutter 205 is positioned below the mold opening / closing rod 42, the mold opening / closing rod 42 is pushed up by the rising of the mold closing shutter 205, and the movable mold mounting plate
41 is pushed up toward the fixed mold mounting plate 32 by a stronger tightening force, and the movable side mold plate and the fixed side mold plate are tightly clamped (step 504).

When the mold clamping is completed, the nozzle 93 of the injection device is then joined to the sprue of the stationary mold plate (step 505). As shown by the imaginary line in FIG. 10, the injection device is in a state in which the nozzle 93 is located at a higher position and is inclined. At this time, the piston rods 98a and 98b are extended by the operation of the hydraulic cylinders 97a and 97b. Therefore, the support rod 96 is pushed up, and the cylinder head 92b connected to the support rod 96 via the T-shaped joint 95 and the support rod 94 is pushed up.
In the state where the cylinder head 92b is pushed up, the injection device is such that the support block 60 supporting the injection device is
The bearing plate 28 is in a state of swinging and tilting about the shaft 51a and the shaft 71a. Then, from this state, the hydraulic cylinders 97a and 97b are operated and the piston rod
Pull back 98a and 98b. As a result, the T-shaped joint 95 is pulled down via the support rod 96, and the cylinder head 92b is pushed down via the support rod 94. Therefore, the injection device swings in the counterclockwise direction from the position indicated by the imaginary line in FIG. 10 about the shafts 51a and 71a, and the nozzle 93 located at the tip of the cylinder head 92b is fixed to the fixed side mold plate. Will be joined to the sprue.

The operation of joining the nozzle 93 to the sprue will be described for each of the three embodiments shown in FIGS. 14 to 21.

In the case of the embodiment shown in FIGS. 14 to 16,
By the swing of the injection device, the guide pin 113 provided on the cylinder head 92b rubs against the inner wall of the guide groove 114a of the positioning block 114 on the side far from the support block 110 and enters. Therefore, the guide pin 113
Is pushed by the inner wall and slightly moves to the support block 110 side. Since the support block 110 is in a state of being pressed against the side surface of the fixed die mounting plate 32 by the restoring force of the returning means 112, when the guide pin 113 moves by receiving the reaction force from the inner wall, the supporting block 110 is returned. 14 is guided by the fixing bolt 111 and slides to the right from the state shown in FIG. 14 to the state shown in FIG. In this state, the nozzle 93 attached to the tip of the cylinder head 92b is joined to the sprue. That is, even when the cylinder body 92a and the cylinder head 92b of the injection device are deformed by heat, the nozzle 93 is reliably positioned and joined to the sprue.

By the way, the bearing plate 28 is attached to the support block 110.
Is fixed to the bearing plate 28.
Since it is supported by the shaft 51a and the shaft 71a, the support block 60 moves in the same direction as the support block 110. Then, since the supporting block 60 supports the injection device, the injection device also moves in the same direction. Further, the measuring input gear 51 is fitted to the shaft 51a,
The injection input gear 71 is fitted to the shaft 71a, and the measurement transmission gear 29a and the injection transmission gear 29b are meshed with the gears 51 and 71, respectively, so that the shaft 51a and the shaft 71a are engaged.
When the bearing block 60 moves together with the support block 60, the metering transmission gear 29a and the injection transmission gear 29b also move in the same direction.
28 will move in the same direction. At that time, since the first output shaft 24a to which the measurement transmission gear 29a is fitted and the second output shaft 24b to which the injection transmission gear 29b is fitted have the universal joints 26a and 26b, These transmission gears
The above movement of 29a and 29b will be allowed.

In the embodiment shown in FIGS. 17 and 18, when the injection device swings to join the nozzle 93 to the sprue, the guided portion 119 formed on the cylinder head 92b is moved to the positioning block. The guide projection 118a of the guide 118 enters the sprue. Therefore, the cylinder head 92b is moved toward the support block 115,
Therefore, the support block 115 moves to the right from the position shown in FIG. 17 against the restoring force of the returning means 117, and enters the state shown in FIG. That is, the cylinder head 92b is guided by the contact with the positioning block 118, and the nozzle 93 joins with the sprue. Therefore, even if the cylinder body 92a and the cylinder head 92b are deformed by heat, the nozzle 93 can be reliably positioned.

In the case of the embodiment shown in FIGS. 19 to 21,
When the injection device swings and the nozzle 93 joins to the sprue, the guide pin 123 of the cylinder head 92b moves into the guide groove 12
The inner wall on the side closer to the support block 120 of 4a will be rubbed in to enter. Therefore, the cylinder head 92b is pushed and moved in the direction opposite to the support block 120, that is, in the left direction in FIG. 19, when the guide pin 123 receives the reaction force from the inner wall. Therefore, the support block 120
Is guided by the fixing bolt 121 and moves toward the fixed die mounting plate 32 against the restoring force of the return spring 122.
The state shown in 20 is reached. In this state, the nozzle 93 is joined to the sprue. That is, even if the cylinder body 92a or the cylinder head 92b is deformed by heat, the nozzle 93 is reliably positioned and joined to the sprue.

In the embodiment shown in FIGS. 19 to 21, when the nozzle 93 is joined to the sprue, the injection device must move in the opposite direction to the case of the embodiment shown in FIGS. 14 to 16 described above. become. Even in this case, the support block 12
With 0, the shaft 51a and the shaft 71a move in the same direction, and the metering transmission gear 29a and the injection transmission gear 29b move in the same direction, but the first output shaft 24a and the second output shaft 24b respectively These transmission gears 29 are provided by the universal joints 26a and 26b provided.
Movements of a and 29b will be allowed.

When the nozzle 93 is joined to the sprue of the stationary mold plate as described above, the molding material plasticized by the heating cylinder is injected into the mold (step 506).
).

The power split device 14 is controlled to rotate the output shaft 14b, and the third output shaft 14a is kept stopped. When the output shaft 14b rotates, the pulley 22a, 20b fitted to the output shaft 14b and the pulley 22 via the belts 21a, 12b.
a and 22b rotate respectively. When injecting the injection device, the clutch 25a provided on the first output shaft 24a is disengaged so that the rotation of the pulley 22a is not transmitted to the metering transmission gear 29a. That is, only the clutch 25b provided on the second output shaft 24b is connected to rotate only the second output shaft 24b. When the second output shaft 24b rotates, the injection transmission gear 29b fitted at the tip portion rotates, so that the shaft 71a fitted at one end with the injection input gear 71 meshed with the injection transmission gear 29b rotates. The injection drive gear 72 fitted to the other end of the shaft 71a rotates. Then, the bearing block 82a in which the carriage drive gear portion 84 that meshes with the injection drive gear 72 is formed rotates with respect to the support bracket 60. A female screw portion is formed on the bearing block 82a, and the drive rod 81b is screwed with this female screw portion. Therefore, when the bearing block 82a rotates, the drive rod 81b is rotated.
Will move back and forth with respect to the bearing block 82a. A pulley portion 83a is formed on the bearing block 82a, and the belt 83c is stretched around the pulley portion 83a and the pulley portion 83b formed on the bearing bracket 82b screwed to the drive rod 81b. The rotation of the bearing block 82a is transmitted to the bearing block 82b, and the drive rod 81b moves back and forth with respect to the bearing block 82b. Moreover, since the pitches of the male screws formed on the drive rods 81a and 81b are equal and the speed ratio between the pulley portions 83a and 83b is 1: 1, the amount of advance / retreat of the drive rod 81a and the drive rod 81b is equal. Since the carriage 73 is fixed to the base ends of the drive rods 81a and 81b, the drive rods
The carriage 73 also moves back and forth as the carriages 81a and 81b move back and forth.

FIG. 6 is a view showing a state before injection, in which the drive rods 81a and 81b are respectively screwed into the bearing blocks 82a and 82b near the tips thereof. In this state, the molding material supplied from the hopper (not shown) to the heating cylinder is heated, appropriately plasticized, and sent to the cylinder head 92b. The bearing blocks 82a and 82b rotate to drive the drive rod 81.
When a and 81b move forward toward the cylinder head 92b side, the carriage 73 fixed to the base ends of these drive rods 81a and 81b also moves forward. Since the joint portion of the screw drive shaft 65 and the screw shaft 90 is located at the center of the carriage 73 and the respective shaft ends are supported, the carriage drive 73 moves forward to advance the screw drive shaft 65 and the screw shaft 90. The shaft 90 is also pushed by the carriage 73 and moves forward. Since the screw drive shaft 65 is supported by the bearing block 63 via a spline,
The screw drive shaft 65 is allowed to move with respect to the bearing block 63. Further, since the screw shaft 90 is inserted through the central portion of the support block 60, the screw shaft 90 is allowed to move with respect to the support block 60.

The tip of the screw shaft 90 is located inside the cylinder body 92a. When the screw shaft 90 advances from the position shown in FIG. 6 to the position shown in FIG. 7, the molding material supplied into the heating cylinder is supplied. An appropriate pressure is applied to the nozzle and the nozzle 93 injects it into the mold.

When the injection is completed, the cooling of the material in the mold is started, and the injection device measures the weight in preparation for the next injection (step 507).

The output shaft 14b of the power split device 14 is kept rotating and the third output shaft 14a is kept stopped. When the injection device is operated for metering, the clutch 25a provided on the first output shaft 24a is connected and the pulley 22
The rotation of a is transmitted to the metering transmission gear 29a, and the second output shaft 24b
The clutch 25b provided on the above is disengaged so that the rotation of the pulley 22b is not transmitted to the injection transmission gear 29a. When the first output shaft 24a rotates, the weighing transmission gear 29a fitted to the tip end portion thereof.
Is rotated, the shaft 51a to which the measurement input gear 51 meshed with the measurement transmission gear 29a is fitted rotates. Therefore, the pulley 5 fitted on the shaft 51a
2 rotates, and the transmission shaft 53 having the transmission pulley 55, which is connected to the pulley 52a via the belt 56, fitted at one end thereof rotates, and the transmission shaft 53 is fitted to the other end of the transmission shaft 53. The attached transmission gear 54 will rotate. Since the screw drive gear 64 meshes with the transmission gear 54, the bearing block 63 provided with the screw drive gear 64 rotates with respect to the support bracket 62. Since the bearing block 63 supports the screw drive shaft 65 via the spline, the screw drive shaft 65 also rotates.

A screw shaft 90 is connected to the tip of the screw drive shaft 65, and the screw shaft 90 rotates together with the rotation of the screw drive shaft 65. FIG. 7 is a diagram showing a state in which the injection has been completed, and the injection device starts the metering operation from this state. When the molding material is supplied from the hopper (not shown) into the heating cylinder, the screw portion 91 formed on the screw shaft 90 is rotated to heat the molding material in the heating cylinder and kneading the cylinder body from the cylinder body 92a. It will be pushed to 92b. When the molding material is fed into the cylinder head 92b, the screw portion 91 receives back pressure and the screw shaft 90 and the screw drive shaft 65 retract. Since the screw shaft 90 is inserted into the support block 60, this retreat is allowed, and the screw drive shaft 65 is connected to the bearing block 63 by the spline, so this retreat is allowed.

When the screw shaft 90 retracts, the carriage 73 linked to the screw shaft 90 also retracts. The drive rods 81a and 81b are provided on the carriage 73.
Is fixed, the drive rods 81a and 81b also retract. Since the bearing block 82a is screwed onto the drive rod 81a, the backward movement of the drive rod 81a causes the bearing block 82a to rotate with respect to the support block 60. When the bearing block 82a rotates, the carriage drive gear 84 formed integrally with the bearing block 82a rotates, so the injection drive gear 72 meshing with the carriage drive gear 84 rotates and the shaft 71a rotates. Will be done. Then, the injection input gear 71 fitted on the shaft 71a rotates. Since the injection transmission gear 29b meshes with the injection input gear 71, the injection transmission gear 29b also rotates, and the second output shaft 24b fitted with the injection transmission gear 29b also rotates. Since the clutch 25b provided on the second output shaft 24b is disengaged, the rotation of the second output shaft 24b is not transmitted to the pulley 22b.

Moreover, since the brake means 27 is provided on the second output shaft 24b, the brake means 27 is provided.
The rotation of the second output shaft 24b can be stopped by operating the. When the rotation of the second output shaft 24b is stopped by the braking means 27, this braking action is generated via the injection transmission gear 29b, the injection input gear 71, the shaft 71a, the injection drive gear 72, and the carriage drive gear portion 84. This is transmitted to the bearing block 82a and the rotation of the bearing block 82a is stopped. Therefore, the drive rod 81a screwed into the bearing block 82a is stopped, and the carriage 73 cannot move backward. Since the rotation of the first output shaft 24a continues to be transmitted to the screw drive shaft 65, the screw shaft 90
Continues to rotate, and as the screw part 91 rotates, the molding material continues to be sent to the tip part.

When the screw shaft 90 retracts, a reaction force due to the back pressure is applied to the load cell 76, and the magnitude of the back pressure is detected. This back pressure is
90 to the screw drive shaft 65, and the thrust bearing 78 from the flange portion 65a formed on the screw drive shaft 65.
And is transmitted to the load cell 76 via the spacer 77.
At this time, if the reaction force generated by the back pressure is overloaded to the load cell 76 by appropriately setting the shape and dimensions such as the thickness and outer diameter of the flange portion 65a, the flange portion 65a can be used. Since the portion 65a is appropriately bent and deformed, it is not necessary to increase the safety factor regarding the load condition of the thrust bearing 78. That is, the back pressure applied to the load cell 76 can be relieved by the deformation of the flange portion 65a, and the load condition of the load cell 76 and the thrust bearing 78 can be relaxed.

When the back pressure detected by the load cell 76 is smaller than a preset threshold value, it means that the molding material has not been sufficiently pushed in, so that the brake means 27 is operated and the screw is operated. Stop the retraction of axis 90. The brake means 27 is released when the molding material is sufficiently supplied and the back pressure becomes larger than the threshold value. When the brake means 27 is released, the screw shaft 90 retracts,
The back pressure applied to the load cell 76 will gradually decrease. When it becomes smaller than the threshold value, the braking means 27 is operated again to stop the backward movement of the screw shaft 90. If the screw shaft 90 retracts to a predetermined position (step 508), this position is detected by a sensor such as a limit switch or an optical switch (not shown), and at that position, a predetermined amount of molding material is supplied to the heating cylinder. Therefore, the weighing operation is stopped.

When the material injected into the mold by the above-described injection operation is cooled (step 509), the mold opening operation is performed.

In the mold clamping operation described above, the movable mold mounting plate 41
The mold clamping piston 204, which had been pressed against the fixed mold mounting plate 32 with high pressure, is stopped to remove this high pressure (step 5
Ten). Next, the shutter drive cylinder 206 is operated to retract the mold clamping shutter 205 to the open position (step 511). Then, the third output shaft 14a of the power branch device 14
Is operated in the opposite direction of the mold clamping operation. At this time, the braking device 40 is operated to rotate the template drive shaft 38 at a low speed. The rotation of the template drive shaft 38 causes the rack portion 42a to move.
Since the pinion gear 39 meshing with is rotated in the direction opposite to the case of the mold clamping operation, the mold opening / closing rod 42 on which the rack portion 42a is formed descends at a low speed and the movable mold mounting plate 41 is fixedly mounted. The mold is to be opened apart from the plate 32 (step 512). When it descends to a predetermined position, the braking device 40 is released to stop the braking of the template drive shaft 38, and the template drive shaft 38 is rotated at a high speed. Therefore, the movable mounting plate
41 will perform mold opening operation at high speed (step 513).
).

When the mold opening operation is performed, the mold opening / closing rod 42 descends, and the lower end portion thereof is located below the mold clamping shutter 205. That is, the mold clamping shutter 205
Is in the open position and the inner diameter of the mold thickness adjusting cylinder 203 is open, so the lower end of the mold opening / closing rod 42 is accommodated inside the mold thickness adjusting cylinder 203 and allowed to descend. It Then, when the mold opening / closing rod 42 descends to an appropriate position, the power branching device 14 is stopped and any output shaft is stopped.
The mold opening operation is stopped by preventing the output from 14a and 14b (step 514).

When the mold opening operation is completed, the hydraulic cylinder 301 of the projecting device 300 is actuated to raise the projecting plate 302 and the projecting pin 303 so that the movable side mold plate attached to the movable mold mounting plate 41 is removed. The molded product is projected and taken out (step 515). If the molded part is ejected,
The hydraulic cylinder 301 is operated in the opposite direction to lower the protrusion plate 302 and the protrusion pin 303 to perform protrusion return (step 516).

In the operation sequence shown in FIG. 26, the nozzle joining step (step 505) is described, but this is for explaining the operation of the injection molding machine according to the present invention, and the same mold is used. In this case, once the nozzle 93 is joined to the sprue, the step 505 is unnecessary, and the steps from step 501 to step 501 are omitted.
The operation sequence up to 516 is one step, and this operation sequence is repeated to form the material.

On the other hand, when exchanging the mold, the nozzle 93
Is separated from the sprue of the fixed-side template. To separate the nozzle 93, the hydraulic cylinder 97
The piston rods 98a and 98b are made to project by actuating a and 97b. When the piston rods 98a, 98b project, the support rods connected to the tips of these piston rods 98a, 98b
96 is pushed up, and the support rod 94 connected to this support rod 96 via the T-joint 95 is pulled up. Since the cylinder head 92b is connected to the support rod 94, the cylinder head 92b is pulled up. Then, the injection device having the cylinder head 92b at the tip end thereof swings from the position shown by the solid line in FIG. 10 to the position shown by the imaginary line with the support block 60 about the shaft 51a and the shaft 71a. . This swinging causes the nozzle 93 to separate from the sprue.

By the way, when the injection device swings about the shafts 51a and 71a, the cylinder head 92b turns, whereas the piston rod 98 of the hydraulic cylinders 97a and 97b.
Although a and 98b move linearly, the hydraulic cylinders 97a and 97b are rotatably supported at their base ends, and the piston rods 98a and 98b are rotatably connected to the support rod 96 and the support rod 96 and the support rod 94. Are rotatably connected to each other via a T-joint 95, the hydraulic cylinders 97a and 97b are appropriately inclined with respect to the axial direction of the cylinder head 92b, as shown by the imaginary line in FIG. It will allow the swivel motion of 92b.

When the injection device is swung, the support block 60 is rotatable with respect to the shafts 51a and 71a, so that these shafts 51a and 71a do not rotate. However, due to the frictional force between the support block 60 and these shafts 51
Even if a and 71a rotate slightly, the clutch
If 25a and 25b are cut, the measurement transmission gear 29a and the injection transmission gear 29b are rotated via the measurement input gear 51 and the injection input gear 71 fitted to these shafts 51a and 71a, respectively, and the The output shaft 24a and the second output shaft 24b are only slightly rotated.

When the nozzle 93 is separated from the sprue, the restraining force for positioning the nozzle 93 acting on the cylinder head 92b is released. That is, in the embodiment shown in FIGS. 14 to 16, the guide pin 113 is separated from the positioning block 114, and in the embodiment shown in FIGS. 17 to 18, the guided portion 119 of the cylinder head 92b is the guide protrusion 118a.
The guide pin 123 is separated from the positioning block 124 in the embodiment shown in FIGS. 19 to 21. Therefore, the support blocks 110, 115, 120 slide under the restoring force of the returning means 112, 117, 122, respectively.

[0078]

As described above, according to the measuring apparatus for an injection molding machine of the present invention, the flange portion is appropriately bent when a back pressure that causes an overload is applied to the load cell in the measuring process. Since this load is alleviated, the load cell is not overloaded. Moreover, since the flange portion bends and absorbs the overload, it is not necessary to use a thrust bearing having a large withstand load, and it is sufficient if the thrust bearing receives a thrust load when the screw shaft rotates. Therefore, the portion holding the load cell can be downsized and the weight can be reduced, and the injection device can be downsized.

Further, during the metering operation, the power transmission path for the injection operation is cut off, and the amount of the molding material supplied is controlled while stopping and retreating the screw by repeatedly operating and non-operating the braking means. Therefore, it is possible to easily control the metering of the molding material and reduce the cost of the control system.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a weighing device of an injection molding machine according to the present invention, which is a cross-section taken along an axis for explaining a joint between a screw drive shaft and a screw shaft and a relationship with a carriage. It is a figure.

FIG. 2 is a schematic plan view illustrating an output shaft from a power branch device of a main drive source suitable for driving a weighing device of an injection molding machine according to the present invention.

FIG. 3 is a schematic front view of FIG.

FIG. 4 is a schematic right side view of FIG.

FIG. 5 is a schematic perspective view for explaining a metering operation unit of the injection device, a cylinder head unit, and a fixed mounting plate.

FIG. 6 is a schematic plan view showing a part of the injection device for explaining the weighing operation part and the injection operation part, showing a state after the end of the measurement operation and before the start of the injection operation.

FIG. 7 is a schematic plan view showing a part of the injection device for explaining the weighing operation part and the injection operation part, showing a state after the injection operation is completed and before the measurement operation is started.

FIG. 8 is a perspective view from obliquely above showing an outline of an injection molding machine equipped with the weighing device according to the present invention.

FIG. 9 is a side perspective view showing the outline of an injection molding machine provided with the weighing device according to the present invention.

FIG. 10 is a schematic front view of an injection molding machine equipped with the weighing device according to the present invention.

FIG. 11 is a left side view of an injection molding machine equipped with the weighing device according to the present invention.

12 is a plan view of FIG. 10 with a part cut away.

13 is a schematic horizontal sectional view of a central portion of FIG.

FIG. 14 is a front view of the first embodiment for explaining the nozzle positioning mechanism of the injection device, showing a state before the nozzle is positioned.

FIG. 15 shows a state where the nozzle is positioned in the first embodiment shown in FIG.

16 is a plan view of the first embodiment shown in FIG.
A part is cut away and shown.

FIG. 17 is a front view of the second embodiment for explaining the nozzle positioning mechanism of the injection device, showing a state before the nozzle is positioned.

FIG. 18 shows a state in which the nozzle is positioned in the second embodiment shown in FIG.

FIG. 19 is a front view of the third embodiment for explaining the nozzle positioning mechanism of the injection device, showing a state before the nozzle is positioned.

FIG. 20 shows a state in which the nozzle is positioned in the third embodiment shown in FIG.

FIG. 21 is a plan view showing a modified example of the third embodiment shown in FIG. 19, with a part cut away.

FIG. 22 is a schematic front view illustrating a drive mechanism of the mold clamping device.

FIG. 23 is a schematic front view illustrating the drive mechanism of the mold clamping device, showing a state in which the mold thickness is adjusted when the thickness of the mold plate of the mold is relatively small.

FIG. 24 is a schematic front view illustrating the drive mechanism of the mold clamping device, showing a state in which the mold thickness is adjusted when the mold plate thickness of the mold is relatively large.

FIG. 25 is a view for explaining the mold thickness adjusting mechanism of the mold clamping device, and is a schematic plan view.

FIG. 26 is a view for explaining the operation sequence of the injection molding machine provided with the weighing device according to the present invention.

[Explanation of symbols]

 1 Base 3 Support 10 Drive 12 Motor 14 Power Divider 14a Output Shaft 14b Output Shaft 20a, 20b Pulleys 21a, 22b Belt 22a, 22b Pulley 24a First Output Shaft 24b Second Output Shaft 25a, 25b Clutch 26a, 26b Universal Joint 27 Braking means 28 Bearing plate 29a Weighing transmission gear 29b Injection transmission gear 30 Mold clamping device 32 Fixed type mounting plate 51 Weighing input gear 51a Shaft 60 Support block 61 Base plate 62 Support block 64 Screw drive gear 65 Screw drive shaft 65a Flange 65b Boss 65c Connection hole 71 Injection input gear 71a Shaft 72 Injection drive gear 73 Carriage 73a Housing 74 Cover plate 75 Bushing 76 Load cell 77 Spacer 78 Thrust bearing 81a, 81b Drive rod 84 Carriage drive gear 90 Screw shaft 90a Base end 90b Neck part 91 Screw part 92a Cylinder body 92b Cylinder head 200 Mold thickness adjustment unit 300 Projection device

Claims (3)

[Claims] 1. A weighing device of an injection molding machine, which detects a back pressure applied to an injection mechanism member at the time of measuring a molten material and controls the retreat of the injection mechanism member to measure the molten material. A load cell for receiving via the flange portion is provided, a bearing for receiving rotation of the flange portion is interposed between the flange portion and the load cell, and the injection mechanism member is inserted from the load cell through the flange portion during injection. A metering device for an injection molding machine, characterized in that the flange portion is appropriately bent when a load of a predetermined magnitude is applied while being moved forward. 2. The molten material is pushed to the nozzle portion by the rotation of a screw rotatably provided in the heating cylinder, the back pressure applied to the screw is detected, and the backward movement of the screw is controlled to control the molten material. In a screw type injection molding machine equipped with an injection device for performing an injection operation by advancing the screw after the measurement, and providing a braking means in the middle of a power transmission path for advancing and retracting the screw. A metering device for an injection molding machine, characterized in that the transmission path of the advancing / retreating power is cut when the screw is rotating, and the back pressure applied to the screw at the time of metering is controlled by the operation and non-operation of the braking means. 3. The molten material is pushed to the nozzle portion by the rotation of a screw rotatably provided in the heating cylinder, the back pressure applied to the screw is detected, and the backward movement of the screw is controlled to control the molten material. In a metering device of a screw type injection molding machine equipped with an injection device that performs a metering operation of, and advances the screw after the metering to perform an injection operation, a load cell that receives the back pressure through a flange portion is provided, Between the load section and the load cell, a bearing for receiving the rotation of the flange is interposed, and a braking means is provided in the middle of a power transmission path for advancing and retracting the screw, and the advancing and retracting power is transmitted during the rotation operation of the screw. The path is cut, the back pressure applied to the screw during metering is controlled by the activation and deactivation of the braking means, and the A screw type injection molding machine weighing device characterized in that the flange portion is appropriately bent when a predetermined amount of load is applied while advancing the screw from the cord cell through the flange portion. .