JP2629547B2 - Lubrication device for toggle mechanism in injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention plasticizes a resin material,
The present invention relates to a lubricating device that supplies a lubricating oil to a connection portion of a toggle mechanism in a mold clamping device or the like provided in the injection molding machine for injecting this into a mold to mold a resin product.

[0002]

2. Description of the Related Art In general, an injection molding machine is used for molding a synthetic resin product.
2. Description of the Related Art There is known a so-called toggle injection molding machine in which the driving force of a hydraulic cylinder serving as a driving source is transmitted to a mold via a toggle mechanism.

FIG. 6 shows a general toggle type injection molding machine. In FIG. 6, reference numeral 1 denotes a fixed plate, 2 denotes an end plate, and a tie bar 3 is installed between the fixed plate 1 and the end plate 2. Tie bar 3
A movable platen 4 is supported in a reciprocating manner, and a fixed die 5 and a movable die 6 are fixed to the fixed platen 1 and the movable platen 4, respectively. Then, the driving force of the hydraulic cylinder 7 provided on the end plate 2 is transmitted to the movable platen 4 via the toggle mechanism 8.
When the movable platen 4 is moved, the fixed mold 5 and the movable mold 6 are clamped, whereby the molten synthetic resin material injected into the mold cavity is molded. .

[0004] The toggle mechanism 8 comprises a plurality of links rotatably connected to each other by means of pins. The details of the structure are provided on the end plate 2 and the movable platen 4 as shown in FIGS. Brackets 9 and 10 are fixedly mounted, and a face piece 11 is connected to the bracket 9, and a toggle piece 12 is connected to the bracket 10 by a pin 14 via a toggle bush 13 so as to be rotatable.
The cross bed 7 a connected to the hydraulic cylinder 7 and the face piece 11 are similarly connected via a joint piece 15.

By the way, the above-mentioned toggle mechanism 8 is usually provided with a means for supplying lubricating oil to the connecting portions in order to prevent wear of the connecting portions of the respective links and to smoothly rotate the connecting portions. Conventionally, as means for supplying the lubricating oil to the connecting portion of the toggle mechanism 8 of this type, as shown in FIGS. 9 and 10, a plurality of oil grooves 13a are formed on the inner surface of the toggle bush 13 and the oil grooves 13a are formed. Lubricating oil such as grease is filled through a space 16 formed inside the
An oil film is formed in a gap between the oil film and the oil.

[0006]

However, the above-described means causes the following inconveniences. That is, the grease or the like filled in the oil groove 13a is gradually consumed according to the operation of the toggle mechanism 8. For this reason, the grease or the like must be refueled on a regular basis.
Cannot prevent the wear of the connecting portion. However,
Since the torque mechanism 8 having the above configuration is configured by connecting a large number of members with a large number of connecting portions, it is very troublesome to periodically perform an operation of supplying grease or the like. However, there is a problem that it is extremely difficult to accurately refuel.

To solve the above problem, it is conceivable to increase the number of oil grooves 13a formed on the inner surface of the toggle bush 13 or to increase the width of the oil groove. This may cause problems such as a decrease in the strength of the body of the toggle bush 13 and the like, which is not practical.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is an apparatus for automatically supplying lubricating oil to a connecting portion of a toggle mechanism provided in an injection molding machine. It is an object of the present invention to provide a lubricating device for extending the life of a mechanism.

[0009]

According to the present invention, there is provided a lubricating device for a toggle mechanism in an injection molding machine, wherein a plurality of links are rotatably connected by pins via bushes. A hollow portion filled with lubricating oil and a lubricating oil supply passage for guiding the lubricating oil in the hollow portion to the outside are formed, and the lubricating oil in the hollow portion is passed through the lubricating oil supply passage to the pin outer surface and the bush. A discharge mechanism is provided between the inner surface and the discharge mechanism, and a counter that counts the number of operations of the toggle mechanism is provided, and a control device that controls driving of the discharge mechanism based on a count output of the counter is provided. It is characterized by the following.

[0010]

In the lubricating device for the toggle mechanism in the injection molding machine of the present invention, a lubricating oil is filled in a hollow portion formed inside a pin constituting the toggle mechanism. When the injection molding machine is driven, the number of times of operation of the toggle mechanism is counted by a counter, and when this count reaches a certain number, the control device operates the discharge mechanism, whereby the lubricating oil flows between the pin and the bush. Is discharged. For this reason, lubricating oil is always supplied to the connection part of the toggle mechanism accurately in accordance with the number of times the toggle mechanism is operated.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show an embodiment of a lubricating device for a toggle mechanism in a mold clamping device of an injection molding machine according to the present invention. Reference numeral 21 denotes a pin constituting a connecting portion of the toggle mechanism. The pin 21 includes a pin body 22 and
It is schematically constituted by a lid plate 23 detachably fixed to an end of the pin main body 22. The pin body 22 has a plurality of annular grooves 21a formed in parallel at an appropriate interval in the pin axis direction on the outer peripheral portion thereof, a hollow portion 24 formed inside and opening at one end, Pin body 22
A plurality of lubricating oil supply passages 25 penetrating through the respective annular grooves 21a toward the outer peripheral surface side, and a sealing port 26 through which the hollow portion 24 penetrates the other end surface are formed.

In the hollow portion 24, a first seal housing 27 is slidably provided in the axial direction of the hollow portion 24. The first seal housing 27 has a peripheral groove 27a formed in an outer peripheral portion thereof, and a cup seal 28 is interposed in the peripheral groove 27a so that the pin body 22 is formed.
The airtight state with the inner surface side of the vehicle is maintained.
Further, the inside of the first seal housing 27, that is, the filling chamber 24a, is filled with lubricating oil such as grease through the sealing port 26. The sealing port 26 has a hollow portion 24
A plug 26a and the like are screwed in to seal outflow of the lubricating oil therein.

On the other hand, on the opening 24a side of the hollow portion 24,
A second seal housing 29 is interposed. The second seal housing 29 has a through hole 29a formed at the center thereof and a peripheral groove 29b formed at the outer peripheral portion thereof. The airtight state with the inner surface side of the vehicle is maintained. Then, the second seal housing 29
Are fixed to the cover plate 23 by screws 31 and the cover plate 23
Is fixed to the other end of the pin body 22 by a screw 32. The cover plate 23 has the through hole 29a at the center thereof.
Through hole 23a formed with an internal thread on the inner surface side
Are formed in the through hole 23a.
Is screwed.

The nipple 33 has a hollow portion 33a communicating with the through hole 29a at the center thereof, and a plurality of locking projections 33b formed at the rear end. A tube 34 having a locking projection 34a engaging with the locking projection 33b is engaged with the locking projection 33b.
The tube 34 is firmly fixed to the nipple 33 by attaching the tightening member 35 from the outside of the tube 4. An air delivery mechanism is connected to the pipe 34. The air delivery mechanism is connected to the air compressor E.
And supplies high-pressure air to the pin 21 side under the control of a control device described later.

Air is appropriately supplied to the pin 21 configured as described above by the control device 40 shown in FIG. In FIG. 2, reference numeral 41 denotes a cycle counter. The cycle counter 41 counts the number of times the toggle mechanism having the pin 21 is operated. The count output is sent to a comparator 42. I have. On the other hand, the setter 43 sets the oiling interval in accordance with the number of times the toggle mechanism is operated, and the set value can be input to the comparator 42.

The comparator 42 compares the result counted by the cycle counter 41 with the set value set in the setter 43, and outputs an output signal to the sequence circuit 44 when the counted result becomes larger than the set value. It is designed to be sent. The sequence circuit 44 controls the air solenoid valve 46 of the air delivery mechanism for a set time set by the timer 45.

Next, the operation of the above lubricating device will be described. First, before the operation of the injection molding machine is started, the refueling interval based on the number of times the toggle mechanism is operated is input to the comparator 42 as numerical information by the setting device 43. In this state, when the injection molding machine is operated, the cycle counter 41 counts the number of times the toggle mechanism operates, and this count output is sent to the comparator 42. When the operation of the injection molding machine is performed for a long period of time and the count output of the cycle counter 41 becomes larger than the value set by the setter 43, an output signal is sent from the comparator 42 to the sequence circuit 44. The sequence circuit 44 operates the air solenoid valve 46 for a set time set in the timer 45. Accordingly, the air delivery mechanism supplies high-pressure air to the pressurizing chamber 24b between the first seal housing 27 and the second seal housing 29 in the hollow portion 22 through the pipe 34 and the nipple 33.

Thus, the pressurizing chamber 24b of the hollow portion 22
Is supplied to the first seal housing 27.
Is pressed for a certain time. As a result, the lubricating oil filled in the filling chamber 24a of the hollow portion 22 of the pin 21 is discharged to the outer peripheral surface of the pin 21 and the inner peripheral surface of the toggle bush (not shown) through the lubricating oil supply passage 23.

This series of operations will be described with reference to FIG. In the figure, A indicates the operation ON / OFF of the toggle mechanism,
B indicates a signal transmitted from the cycle counter 41 to the comparator 42, and C indicates an output signal from the comparator 42 to the sequence circuit 44. First, every time the toggle mechanism operates, the cycle counter 41 counts the number of times (waveform B).
The count output is sent from the cycle counter 41 to the comparator 42. Since the set value is stored in the comparator 42 in advance, it is output to the sequence circuit 44 in accordance with the set value (waveform C).

FIG. 4 is a flow chart showing a series of these operations. As shown in FIG. 4, the operation of the injection molding machine is performed, and after the operation of the toggle mechanism is started, the number of operations is cycle-counted. When the count value is smaller than the set value, the cycle count is continued. Then, when the counted value becomes larger than the set value, an air ON output is made, and supply is performed for a certain time. Thus, lubricating oil is supplied from the pin 21.

Therefore, the lubricating device supplies lubricating oil for a certain period of time when the number of times of operation of the toggle mechanism becomes larger than a certain number of times, so that all the supply of lubricating oil to the toggle mechanism is automatically performed. The life of the toggle mechanism can be extended.

FIG. 5 shows another embodiment different from the above-described embodiment, in which a plurality of annular grooves 5 formed in a pin 50 are provided.
0a are made to cross each other. In the case of such a shape, the oil film between the pin and the toggle bush is formed evenly, and a better lubrication state can be obtained.

[0023]

As is apparent from the above description, according to the lubricating device for the toggle mechanism in the mold clamping device of the injection molding machine of the present invention, lubricating oil can be supplied accurately in accordance with the number of times the toggle mechanism is operated. This makes it possible to reduce the complexity of the operation and to prolong the life of the toggle mechanism.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a lubricating device of a toggle mechanism in an injection molding machine shown as one embodiment of the present invention.

FIG. 2 is a block diagram showing a control unit of the device shown in FIG.

FIG. 3 is a waveform chart showing an operation state of each unit of the control unit.

FIG. 4 is a flowchart showing an operation state of the apparatus.

FIG. 5 is a side view showing an appearance of a pin of a toggle mechanism in an injection molding machine shown as another embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a toggle injection molding machine.

FIG. 7 is a plan sectional view of a main part of a toggle mechanism of the injection molding machine.

FIG. 8 is a side view of a main part of the toggle mechanism.

FIG. 9 is a vertical sectional view of a main part showing a lubrication structure of a toggle mechanism in a conventional injection molding machine.

FIG. 10 is a perspective view of a relevant part of a toggle bush used in the toggle mechanism.

[Explanation of symbols]

 Reference Signs List 5 fixed type 6 movable type 8 toggle mechanism 11 face piece 12 toggle piece 13 toggle bush 21, 50 pin 24 hollow portion 25 lubricating oil supply path 40 control device 41 cycle counter

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-112017 (JP, A) JP-A-1-17697 (JP, A) JP-A-61-155112 (JP, A)

Claims (1)

(57) [Claims] 1. A toggle mechanism in an injection molding machine in which a plurality of links are rotatably connected by pins with bushes interposed therebetween, wherein a hollow portion in which lubricating oil is filled in the pins, A lubricating oil supply passage for guiding the lubricating oil in the portion to the outside; and a discharge mechanism for discharging the lubricating oil in the hollow portion through the lubricating oil supply passage between the outer surface of the pin and the inner surface of the bush. A counter that counts the number of operations of the toggle mechanism, and a control device that controls the driving of the discharge mechanism based on the count output of the counter. Lubrication device.