JP3352806B2 - Method and apparatus for centering blow pin in blow molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for centering a blow pin in a blow molding machine.

[0002]

2. Description of the Related Art In a blow molding machine, when a parison is conveyed into a cavity of a blow molding die, the parison is held in the die, and the die is fastened by a mold clamping device to be transferred to the die. When the blow pin of the driving device is inserted and pressurized air is blown into the parison from the blow pin, the parison is blow-molded into a container such as a bottle that conforms to the shape of the cavity.

As shown in FIGS. 5 and 6, a driving device for forming a container or the like from a parison has a support at a predetermined height supported on a base 39 via a rail or the like so as to be movable in the front-rear direction. The plate 40 is provided with a plate 41 fixed so that the position can be adjusted in the left-right direction, and a plate 42 fixed so that the position can be adjusted in the vertical direction is supported by the plate 41.
An arm 43 is fixed to the plate 42, a fluid pressure cylinder 44 is fixed to an upper portion of the arm 43, and a guide rod 45 is supported by a lower portion of the arm 43.

[0004] A slide block 47 is provided which is connected to a piston rod 46 hanging down from a fluid pressure cylinder 44 and which can move up and down along a guide rod 45. An air blowing nozzle is provided at the center of the slide block 47, and a blow pin 48 having a cooling water channel is provided at the outer periphery thereof. The blow pin 48 is fixed to a stripper plate 49 which is connected and supported at the lower end of the guide rod 45. 50.

As shown in FIG. 7, a nozzle body 51 for connecting a pipe for supplying cooling water and air is connected to the upper end of the blow pin 48, and a screw rod 52 is connected to the nozzle body 51. Rod 52
Is a support block 53 fixed to the slide block 47
And project above the slide block 47. The screw rod 52 has its jig turned at its upper end to adjust the degree of screwing, and adjusts the amount of contact between the cutting sleeve 48a integral with the blow pin 48 and the counter plate 55 provided on the mold 54. Things.

Therefore, as shown in FIG.
The molds 54, 54 having a half-split configuration clamped with a cylindrical parison under the lower part 8 move via a mold-clamping device (not shown), and the counters with the blow-in ports of the molds 54, 54 are provided. When the blow pin 48 is located directly above the plates 55, 55,
Oil or air is supplied to the fluid pressure cylinder 44 to extend the piston rod 46 and push down the slide block 47 along the guide rod 45.

[0007] As shown by a phantom line in FIG.
8 hangs down from the stripper bush 50 and is inserted into the air inlet. Therefore, air is blown from the blow pin 48, and the parison expands along the cavities of the molds 54, 54, whereby the molded article 56 is molded.

In this molding, if the center of the parison held by the mold 54, that is, the center of the blow port 57 of the counter plate 55 is not aligned with the blow pin 48, the opening of the container 56 may be deformed. The top surface of the mouth of the container 56 cannot be finished, resulting in defective products of the container 56 (post-molding). In addition, cutting on the blow pin 48 side which cuts the parison 58 in contact with the counter plate 55. The life of the sleeve 48a is shortened.

Therefore, in producing a hollow product, the centering operation, that is, the centering operation between the mold counter plate and the blow pin is an important factor. In view of this, the centering work currently depends on the operator's many years of experience and intuition, such as performing adjustment by repeating trial and error with the adjustment bolt 53a (FIG. 7).

[0010]

However, depending on the experience and intuition of the operator, accurate centering cannot be performed, and the occurrence of defective products and the counter plate
And it is inevitable that the cutting sleeve 48a is worn away.

In view of the above circumstances, the present invention provides a driving centering method for a hollow molding machine and a device therefor that can be easily and accurately centered even by a non-expert.

[0012]

According to the present invention, a method for centering a blow pin in a blow molding machine according to the present invention includes lowering a driving device of the blow molding machine, and setting a centering device set on an upper surface of a mold. Insert the blow pin, spray fluid toward the blow pin from at least four sides facing each other in the orthogonal direction to the blow pin, measure each back pressure or flow rate, and manually adjust the position of the blow pin so that these values become constant It is characterized by doing.

The blow pin driving centering device in the blow molding machine according to the present invention has a blow port that is rotatable around the blow pin so as to be diametrically opposed to the blow pin of the driving device in the blow molding machine. It has a conduit communicating with the outlet and is connected to a fluid supply source, and has means for confirming the back pressure or flow rate thereof, so that it can be attached to and detached from the upper surface of the mold in the hollow molding machine. Features.

[0014]

After inserting the blow pin into the counter plate of the mold, a fluid is blown out from the blow port, and the blow port is swirled around the blow pin as appropriate to measure the back pressure or the flow rate at that location, and to measure the back pressure or flow rate at each measurement location. When the driving device is moved back and forth and left and right so that the back pressure or flow rate is constant, the blow pin will be located at the center of the counter plate,
Therefore, the centering operation can be completed simply, quickly and easily, and the molding can be produced without deformation of the shape of the mouth of the molded product.

[0015]

Embodiments of the present invention will be described below. Figures 1 and 2
As shown in (1), a mold 3 having a counter plate 2 for inserting a blow pin 1 of a driving device in a blow molding machine mounted on an upper surface is sandwiched and fixed by a mold clamping device. The blow pin 1 is inserted into a center hole 5 having a tapered surface 4 of a counter plate 2. The blow pin 1 is provided with a cutting sleeve 6 formed as a step that abuts the tapered surface 4.

A counter plate 2 is provided on the upper surface of the mold 3.
Holes 7 are radially arranged at predetermined intervals on a circumference having a predetermined radius centered on the center hole 5. This hole 7
The pin 8 is positioned with respect to the mold 3, and a driving centering device 9 is detachably mounted on the upper surface. That is, it can be easily attached and detached without using screws or the like.

The driving centering device 9 includes an outer cylinder 11 having a rectangular flange 10 surrounding the peripheral portion of the counter plate 2, and an inner cylinder inserted into the outer cylinder 11 and rotatable about an axis. A cylindrical body 12, an annular plate 16 fixed to the flange portion 13 of the inner cylindrical body 12 with screws 14 and having a hole 15 into which the blow pin 1 is inserted, and an air outlet radially drilled in a cross section of the annular plate 16 17 and a flow path 18 communicating with the outlet 17
And circumferential grooves 19 and 20 for supplying a fluid such as air to the flow path 18.
And a connection port 21 opened in the circumferential groove 20.

The circumferential groove 19 is formed on the outer peripheral surface of the inner cylindrical body 12.
Numerals 0 are formed so as to coincide with the inner peripheral surface of the outer cylinder 11 respectively. Then, in order to seal the corresponding circumferential grooves 19 and 20, the outer cylindrical body 11 at the upper and lower portions of the circumferential grooves 19 and 20 is formed.
O-rings 22 are arranged in gaps between the inner ring 12 and the inner cylinder 12, respectively. A circumferential groove 24 is formed on a lower outer peripheral surface of the inner cylindrical body 12 at a lower portion of the inner circumferential surface of the outer cylindrical body 11 so as to engage a stop ring 23 projecting in a radial direction. The washer 25 and the stop ring 23 are fixed to the outer cylinder 11 with a holding member 26.

A plunger 27 is attached to the flange portion 13 in order to rotate and position the inner cylinder 12. The plunger 27 is configured by lightly pressing a ball 28 against the upper surface of the outer cylinder 11 with a spring 29.
When the annular plate 16 rotates, it falls into a shallow circular hole cut out on the upper surface of the outer cylinder 11 so that its position can be confirmed.

As shown in FIG. 3, a hose 31 extending from the measuring instrument housing 30 is connected to the connection port 21, and the measuring instrument housing 30 is connected to the fluid switching valve 32 connected to the hose 31.
And a sensor 33 such as a pressure gauge for detecting a supply pressure or a flow rate from the fluid switching valve 32, a digital display 34 for displaying the measured numerical value, and an amplifier 35. The fluid switching valve 32 and the display 34 are driven by electricity supplied from a commercial power supply connection 36. The display 3
4 may be replaced with an analog display 37 such as a pressure gauge as shown in FIG.

Next, a method of centering the blow pin 1 will be described. As shown in FIGS. 1 and 2, after positioning the centering device 9 on the upper surface of the mold 3 with the pin 8, the fluid switching valve 32 is moved. When driven, fluid is supplied from the hose 31 to the connection port 21, and the fluid passes through the circumferential grooves 19 and 20 and the flow path 18 and
7 blows out toward the blow pin 1.

Therefore, the fluid supply pressure or flow rate at this time is read by the display 34 or 37, stored or recorded, and then the inner cylinder 12 is rotated by a predetermined angle (90 degrees). Then, the fluid supply pressure or flow rate at the rotated portion is read by the indicators 34 and 37, stored or recorded, and the inner cylinder 12 is further rotated at a predetermined angle.
The fluid supply pressure or flow rate is read in the same manner as described above. In this way, the fluid supply pressure or flow rate of the blow pin from at least four directions is confirmed or measured.

Next, the confirmed or measured values of the pressure or flow rate are compared, and the blow pin 1 is adjusted by moving the blow pin 1 forward, backward, left, right or any one of them so that the values become equal to each other. This adjustment may be made by moving the driving device back and forth and left and right in the same manner as the above-mentioned conventional method.

Thus, since the blow pin 1 is located at the center of the center hole 5 of the counter plate 2, the shape of the mouth of the molded product is deformed, and a screw thread or the like to be formed on the outer peripheral surface of the mouth is formed. There is no collapse.

The measurement accuracy varies depending on the fluid supply pressure and the diameter (φ) of the outlet 17. As shown in FIG. 4, a pressure adjusting valve 38 and a switching valve 39 are interposed between the fluid switching valve 32 and the sensor 33 so that the pressure (1 to 4 kg) can be adjusted and the pressure of the air supply is switched. The experiment of the change of the measurement accuracy was carried out.

Table 1) shows the air supply when the diameter of the outlet 17 is φ18.0, Table 2) shows the air supply when the diameter is φ18.4, and Table 3) shows the air supply when the diameter is φ17.5. By changing the pressure (1 to 4 kg), A, B,
The example which measured from four directions of C and D is shown. As can be determined from these tables, in the case of φ17.5, the air supply pressure 1
Variations in the measured values at ２2 Kg increase, but are stable at 3 Kg or more. In the case of φ18.0 or more, all stable measurements can be made.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

According to the present invention described above, the back pressure or the flow rate of the fluid is measured at least in four directions around the blow pin, and the blow pin is moved forward, backward, left and right so as to eliminate the difference therebetween, and the center of the counter plate is adjusted. The centering of the blow pin and the shaft center of the blow pin can be omitted, so that the centering work by a skilled person can be omitted, and the numerically accurate centering work can be performed by an unskilled person. Can be simplified, and the occurrence of defective molded products can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a main part according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a schematic configuration diagram of a measuring instrument.

FIG. 4 is a piping diagram showing another example of the measuring instrument.

FIG. 5 is a front view of the driving device.

FIG. 6 is a side view of the driving device.

FIG. 7 is a partially sectional front view of the driving device.

[Explanation of Signs] 1 ... Blow pin 2 ... Counter plate 3 ... Mold 5 ... Center hole 6 ... Screw 9 ... Punch centering device 11 ... Outer cylinder 12 ... Inner cylinder 16 ... Circular plate 17 ... Outlet 18 ... Flow paths 19, 20 ... circumferential groove 21 ... connection port 22 ... O-ring 27 ... plunger 28 ... ball 29 ... spring 30 ... measuring instrument housing 31 ... hose 32 ... fluid switching valve 33 ... sensor 34 ... display

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 49/00-49/80

Claims (2)

(57) [Claims] 1. A driving device of a hollow molding machine is lowered, a blow pin is inserted into a driving centering device set on an upper surface of a mold, and fluid is directed toward the blow pin from at least four sides orthogonal to each other in a direction orthogonal to the blow pin. A method of centering a blow pin in a blow molding machine, wherein the back pressure or the flow rate is measured by spraying, and the position of the blow pin is manually adjusted so that these values become constant. 2. A blower having a blow-out port which is rotatable around the blow-pin in a diametric direction and opposes a blow-pin of a driving device in a blow molding machine, and has a pipeline communicating with the blow-out port. A blow pin driving centering device for a blow molding machine, characterized in that it is connected to a source and has means for confirming the back pressure or flow rate thereof, and is detachable from a die upper surface of the blow molding machine.