JP3420881B2 - Lubrication method and lubrication device for drive device of injection molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cylinder barrel,
A screw provided in the cylinder barrel so as to be rotatable and axially drivable, a drive device including a drive mechanism for driving the screw rotationally and axially, a hydraulic motor for rotationally driving the screw, and the like. The present invention relates to a method for lubricating a drive unit of an injection molding machine provided with the same, and a lubricating method for a drive unit of an injection molding machine, which is capable of surely lubricating even when applied to an injection molding machine with a short molding cycle, and implementation of this method. The present invention relates to a lubrication device used in.

[0002]

2. Description of the Related Art An injection molding machine in which a plasticizing screw is rotationally driven by a hydraulic motor is well known in the art without mentioning the name of the literature, and as shown in FIG. Cylinder barrel 30, this cylinder barrel 30
A screw 31 rotatably and axially drivable therein, a hydraulic motor 32 for rotationally driving the screw 31, a pair of dies not shown in the drawing, and die clamping of these dies It is composed of a mold clamping device and the like. Further, a drive mechanism including a gear driven by the hydraulic motor 32, a rotary bearing bearing a gear shaft, a sliding bearing, or the like is provided in the drive housing 34, and the screw 31 is rotationally driven via this drive mechanism. It is supposed to be done. Further, the screw 31 is provided in the drive housing 34.
There is also provided, for example, a hydraulic piston / cylinder mechanism for driving the shaft in the axial direction. Therefore, the screw 31 is rotatably driven by the hydraulic motor 32 to measure the resin material, and the screw 31 is put on the die which is clamped by the hydraulic piston.
When a metered molten resin is injected by being driven in the axial direction by a cylinder mechanism, a molded product having a desired shape is molded. Again, the screw 31 is rotatably driven by the hydraulic motor 32 to similarly measure and inject the resin material, so that a molded product can be continuously obtained by a so-called injection molding cycle.

By the way, when a molded product is obtained by the molding cycle as described above, the drive mechanism in the drive housing 34 must be lubricated, but conventionally, as shown in FIG. It is designed to be lubricated with drain oil. That is, the drain pipe 35 of the hydraulic motor 32 is connected to the lubricating oil injection port 36 of the drive housing 34, and the lubricating oil discharge pipe 38 is connected to the discharge port 37 of the drive housing 34. Therefore, when the pressure oil in the tank 39 is supplied to the hydraulic motor 32 for measuring the resin material, the hydraulic motor 32 rotates and the working oil returns to the tank 39 from the discharge pipe line 40. At this time, the hydraulic motor 32 Drain oil naturally generated by the rotation of the
5 is supplied to the drive housing 34, and the drive mechanism in the drive housing 34 is lubricated. The lubricating oil provided for lubrication is discharged from the lubricating oil discharge pipe 38 to the tank 39.

[0004]

The conventional lubrication system using drain oil has various advantages as described above. For example, since the drain oil of the hydraulic motor 32 is generated every time the hydraulic motor 32 rotates, that is, in each injection molding cycle, the lubricating oil in the drive housing 34 of the conventional injection molding machine is a new lubricating oil in each injection molding cycle. It has the advantage that the drive mechanism is always lubricated with new lubricating oil. Also,
Since it is lubricated by the drain oil of the hydraulic motor 32 that rotationally drives the screw 31 and there is no need to provide a dedicated hydraulic pump for supplying lubricating oil, the cost of the injection molding machine is also reduced. Further, since a small amount is required for lubrication, the conventional injection molding method has the advantage that the drain oil naturally generated from the hydraulic motor 32 can be used for lubrication without excess or deficiency, and that the lubrication amount need not be specially controlled. . However, there are problems or drawbacks. For example, recent injection molding techniques are diversified, and one injection molding cycle is shortened to 3 to 5 seconds especially in the field of high-speed injection molding. Lubrication of such a high-speed injection molding machine uses conventional drain oil. There is a situation where lubrication is not enough. That is, if the injection molding cycle is short, the hydraulic motor 3 will be discharged before drain oil is discharged.
2 stops, and a state occurs in which the drive device is not filled with drain oil. As a result, the drive mechanism such as the rotary bearing and the slide bearing in the drive housing 34 may generate heat, wear, and the like, which may lead to the worst condition of the drive mechanism being damaged. The present invention is to provide a lubricating method and a lubricating device for a drive unit of an injection molding machine, which solves the above-mentioned problems or drawbacks. More specifically, the present invention provides a lubricating oil for a hydraulic motor that rotationally drives a screw. To provide a method for lubricating a drive unit of an injection molding machine, which can surely lubricate a drive unit of an injection molding machine having a short injection molding cycle, even though it is used for lubrication, and a lubrication apparatus used for implementing the method. It is an object.

[0005]

In order to achieve the above-mentioned object, the present invention is configured to utilize, as a lubricating oil, the exhaust oil that comes out of work from a hydraulic motor that rotationally drives a screw. That is, a first aspect of the present invention, in order to achieve the above object, a cylinder barrel, a screw is provided to be driven in rotation and axially in the cylinder barrel, rotational and axial said screw a drive unit consisting of the drive mechanism or the like for driving, in an injection molding machine having a hydraulic motor for rotating the screw, the lubrication of the drive device, after work from the hydraulic motor, wherein Connected to the outlet of the hydraulic motor
It is configured to be performed by hydraulic oil discharged from the discharge pipe to the oil tank . The invention of claim 2 is composed of a cylinder barrel, the screw being drivably provided in rotation and axially in the cylinder barrel, such as a driving mechanism for driving the rotation and the axial direction of the screw a driving device, in an injection molding machine having a hydraulic motor for rotating the screw, the lubricant conduit is branched from the hydraulic motor of the hydraulic oil discharge line, the lubricating conduit connected to the drive unit Has been done. The invention according to claim 3, the lubrication pipe according to claim 2, the flow control means is provided, and the invention of claim 4, the driving device according to claim 2 or 3, the drive Housed in the housing,
The lubrication line is connected to the lubrication port of the drive housing.

[0006]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIG. The injection molding machine according to the present embodiment is
As shown in FIG. 1, a drive housing 1 is provided. Then, in the drive housing 1, a drive shaft connected to an output shaft of a hydraulic motor described later, a rotary shaft for rotationally driving the screw, a rotary or sliding bearing bearing these shafts, and if necessary, A gear mechanism provided between the drive shaft and the rotary shaft, and a drive device that includes, for example, a hydraulic piston / cylinder mechanism that drives the screw in the axial direction are provided. Further, a working oil, that is, a lubricating oil filling port 2 is provided above the drive housing 1, and a lubricating oil discharge port 3 is provided below the lubricating oil filling port 2. A lubricant oil discharge pipe 4 is connected to the lubricant oil discharge port 3.

A cylinder barrel 6 extends from the drive housing 1 as is well known. A screw 7 is provided in the cylinder barrel 6 so as to be rotatable and axially movable. The rear end of the screw 7 is connected to the rotary shaft in the drive housing 1 and the hydraulic piston.
It is connected to the cylinder mechanism in a known manner. Therefore, the screw 7 can be rotationally driven by the hydraulic motor 10 to measure, and the screw 7 can be axially driven and ejected by the hydraulic piston / cylinder mechanism.

The hydraulic circuit for rotationally driving the screw 7 is connected to a hydraulic motor 10 whose output shaft 16 is connected to the drive shaft in the drive housing 1, and to a pressure oil supply port 11 of the hydraulic motor 10. The pressure oil supply pipe 12 and the discharge pipe 17 that is similarly connected to the discharge port 22 of the hydraulic motor 10 are included. The pressure oil supply pipe 12 extends toward the oil tank 15, and a hydraulic pump 13, a strainer 14 and the like are interposed in the middle thereof. Similarly, the discharge pipe 17 extends toward the oil tank 15, and a heat exchanger 18 such as an oil cooler is provided in the middle of the discharge pipe 17. The heat exchanger 18 controls the oil temperature of the hydraulic oil to keep the physical properties such as the viscosity of the hydraulic oil constant. The discharge pipe 17 itself has a flow resistance of the fluid, and a back pressure is generated when the hydraulic oil is discharged from the hydraulic motor, but the heat exchanger 18 also generates a back pressure of about several kgf / cm ^2. .

From the middle of the discharge pipe 17 of the hydraulic motor 10, a lubricating pipe line 20 having a predetermined diameter and a predetermined length and having a predetermined flow resistance is branched. In the illustrated embodiment, a flow rate adjusting valve 21 is interposed in the lubricating conduit 20 and is connected to the lubricating oil injection port 2 of the drive housing 1 described above.

Next, the operation of the above embodiment will be described. The hydraulic pump 13 is started to measure the resin material. Then, the hydraulic oil in the oil tank 15 is supplied to the hydraulic motor 10 by the hydraulic pump 13, and the hydraulic motor 10 rotates. The rotation of the hydraulic motor 10 is transmitted to the screw 6 via the drive mechanism in the drive housing 1, and the resin material is plasticized in a conventional manner. The plasticized molten resin is injected into the mold clamped by driving the screw 6 in the forward direction by the hydraulic piston / cylinder mechanism. Wait for cooling and solidification, open the mold and take out the molded product. Hereinafter, a molded product is obtained by a similar molding cycle.

Since the hydraulic motor 10 rotates during measurement,
The working oil that has finished the work is reliably discharged to the discharge pipe 17 in each molding cycle. As described above, the discharge pipe 17 itself has a flow resistance of the fluid and the heat exchanger 18 having the resistance.
Since the pressure inside the drive housing 1 is usually atmospheric pressure, which is lower than the pressure inside the discharge pipe 17, some of the discharged hydraulic oil also flows toward the lubrication pipeline 20. . The flowing amount is an amount determined by the flow resistance of the discharge pipe 17 including the heat exchanger 18, the resistance of the lubrication pipeline 20 and the resistance adjusted by the flow rate adjusting valve 21, and this amount of hydraulic oil It is supplied to the drive housing 1. Then, the drive device including the drive mechanism of the screw 7 provided in the drive housing 1 is lubricated. The hydraulic oil provided for lubrication is discharged from the lubricating oil discharge pipe 4 to the oil tank 15.

As described above, according to this embodiment, regardless of the length of the injection molding cycle, the drive device including the drive mechanism of the screw 6 is surely lubricated for each injection molding cycle. Further, there is an advantage that the amount of lubrication at this time can be accurately adjusted by the flow rate adjusting valve 21. The present invention can be carried out without being limited to the above embodiment. For example, instead of the flow rate adjusting valve 21, other oil amount control means such as an orifice or a choke can be used. Furthermore, the oil amount control means can be omitted by appropriately selecting the diameter, length, etc. of the lubricating conduit 20.

[0013]

As described above, according to the present invention, the lubrication of the driving device including the driving mechanism of the screw provided in the cylinder barrel so as to be rotatable and axially driven,
After finishing the work from the hydraulic motor for driving the screw, the exhaust pipe connected to the discharge port of the hydraulic motor opens
Since it is configured to be performed by the hydraulic oil discharged to the oil tank, even if the injection molding cycle, such as high-speed injection molding, is short, the hydraulic motor will surely discharge the finished hydraulic oil to drive it. device ensures that lubricated, unique effects are obtained in the present invention. Further, since it is surely lubricated, troubles such as wear and breakage of the driving device do not occur. Further , according to the present invention, since the lubricating oil is lubricated by the working oil discharged after finishing the work from the hydraulic motor, it is replaced with a new lubricating oil in each injection molding cycle, and the drive mechanism is constantly lubricated with the new lubricating oil. Since it is lubricated by the hydraulic oil of the hydraulic motor that rotationally drives, and it is not necessary to provide a dedicated hydraulic pump or the like for supplying the lubricating oil, the advantages such as cost reduction of the injection molding machine can be naturally obtained. According to another aspect of the invention, since the lubrication pipe is provided with the flow rate control means, in addition to the above-described effects, an effect that the amount of hydraulic oil supplied to the drive device, that is, the amount of lubricating oil can be adjusted without excess or shortage .

[Brief description of drawings]

FIG. 1 is a front view showing a partial cross section of an embodiment of the present invention.

FIG. 2 is a front view showing a conventional example with a partial cross section.

[Explanation of symbols]

1 Drive housing 6 cylinder barrel 7 screws 10 hydraulic motor 17 Discharge pipe 20 Lubricating pipeline 21 Flow rate adjustment valve

Claims (4)

(57) [Claims] And 1. A cylinder barrel (6), and screw (7) which is drivably arranged in the rotational and axial to the cylinder barrel (6) in driving the rotation and the axial direction the screw (7) Drive device including a drive mechanism for
If, in an injection molding machine having a hydraulic motor (10) for rotating said screw (7), the lubrication of the drive device, after work from the hydraulic motor (10), said hydraulic motor ( 10) Connected to the outlet
A method for lubricating a drive unit of an injection molding machine, characterized in that it is performed by operating oil discharged from an exhaust pipe (17) to an oil tank (15) . And wherein the cylinder barrel (6), and screw (7) which is drivably arranged in the rotational and axial to the cylinder barrel (6) in driving the rotation and the axial direction the screw (7) Drive device including a drive mechanism for
If, in an injection molding machine having a hydraulic motor (10) for rotating said screw (7), wherein from the hydraulic fluid discharge line of the hydraulic motor (10) (17) lubrication conduit (20) A lubrication device for a drive unit of an injection molding machine, which is branched, and the lubrication pipeline (20) is connected to the drive unit. 3. A lubrication device for a drive unit of an injection molding machine, wherein the lubrication pipeline (20) according to claim 2 is provided with a flow rate control means (21). 4. The drive device according to claim 2 or 3 is housed in a drive housing (1) and a lubrication line (20) is connected to a lubrication port (2) of the drive housing (1). Lubrication device for drive of injection molding machine.