JP3318740B2 - Injection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device applied to an injection molding machine, and more particularly to a pre-plastic injection device.

[0002]

2. Description of the Related Art An injection device of an injection molding machine melts a resin into a fluid state (plasticization), stores the resin in an amount required for one injection (metering), and pressurizes the molten resin. It has the function of filling (injecting) into a mold.

[0003] Injection devices include an in-line screw type having a single cylinder and a pre-plasticity type having two cylinders.

Referring to FIG. 4 and FIGS. 5 (a) and 5 (b), a conventional pre-plastic injection device includes, for example, a pre-plastic cylinder 11 having a plasticizing screw (not shown).
0, an injection cylinder 120 having an injection plunger (not shown), and a nozzle 14 connectable to a mold (not shown).
0, the pre-cylinder section 110 and the injection cylinder section 12
0, and a rotary path switching unit 130 provided between the two.

[0005] The operation is performed by a melting and sending step in which the resin is melted in the pre-plastic cylinder portion 110 and sent to the injection cylinder portion 120, and after the injection plunger is retracted by the reaction force of the resin to reach a predetermined retracted position, An injection step of injecting a predetermined amount of resin from the nozzle 140 by moving the injection plunger forward.

The rotary path switching section 130 is provided with a crosshead 131 having a space having a circular cross section centering on a passage having a T-shaped cross section and an intersection thereof, and a rotatable rotatably provided in the circular space of the crosshead 131. A valve stud 132 having a T-shaped passage and a hydraulic cylinder 133 for rotating the valve stud 132 via a crank mechanism are provided.

[0007] In the melting and sending step, the rotary path switching unit 130, as shown in FIG.
Between the cylinder 10 and the injection cylinder section 120
32, and at the time of the injection process, FIG.
As shown in (b), the injection cylinder 120 is made into a chamber independent of the pre-plastic cylinder 110 by the valve stud 132, and the interior of the injection cylinder 120 and the nozzle 14
It is switched to communicate with 0.

In the rotary path switching unit 130, as shown in FIG. 6, if the T-shaped passage of the valve stud 132 is not located at a regular position with respect to the T-shaped passage of the crosshead 131, the vicinity of the boundary between the two passages will be determined. A step is formed at. Then, with the operation of the injection molding machine, the resin gradually accumulates on the step portion, and a deposit SD may be generated. The deposit SD causes a molded article defect such as a black spot.

The position of the valve stud 132 relative to the T-shaped passage of the crosshead 131 is affected by the following items.

The positional relationship of the crosshead 131 with respect to the injection cylinder 120, the injection cylinder 120 (or the crosshead 13)
The positional relationship of the hydraulic cylinder 133 with respect to 1), the dimensional tolerance of the hydraulic cylinder 133, the positional relationship between the hydraulic cylinder 133 and the crank mechanism, the dimensional tolerance of the crank mechanism itself, and the positional relationship between the crank mechanism and the valve stud 132.

[0011] Of these, items, and
The valve stud 13 for the T-shaped passage of the crosshead 131 hardly changes with time from the design and assembly.
It is not an item that can be adjusted as a countermeasure against the positional deviation of the T-shaped passage 2.

As a countermeasure against misregistration based on items, a measure using a smaller dimensional tolerance than a general-purpose hydraulic cylinder can be considered, but this is not preferable in terms of cost.

Therefore, generally, adjustment of items, that is, adjustment of the positional relationship between the hydraulic cylinder 133 and the crank mechanism is performed.

[0014]

To adjust the positional relationship between the hydraulic cylinder 133 and the crank mechanism, specifically, the pre-plastic cylinder 110 and the nozzle 140 are removed from the crosshead 131, and the valve stud is passed through the opening of the crosshead 131. While visually checking the 132 passage,
This is performed by turning a screw of a portion of the movable portion of the hydraulic cylinder 133 connected to the crank mechanism. The work of removing each member is a large-scale work, and takes time and effort. Moreover, since a stroke error of the hydraulic cylinder 133 appears,
Such adjustments must be made relatively frequently. In addition, the accuracy of the adjustment depends on the sense of the viewer (for the stepped state).

An object of the present invention is to provide an injection apparatus which can easily and accurately adjust a resin passage and which is useful for obtaining a good molded product.

[0016]

According to the present invention, there is provided a pre-plastic cylinder section for melting and sending out a resin, a nozzle connectable to a mold set in an injection molding machine, and a method for supplying resin from the pre-plastic cylinder section. An injection cylinder portion for injecting a predetermined amount through the nozzle, and a cross-section having a substantially T-shaped cross-section, each of which has a circular cross-section centered on a resin passage facing the pre-plastic cylinder portion, the injection cylinder portion, and the nozzle, respectively, and the intersection thereof. A crosshead having a space portion, a valve stud rotatably provided in a circular space portion of the crosshead and having a resin passage having a substantially T-shaped cross section, and a telescopic device for rotating and driving the valve stud via a crank mechanism. And a movable plastic mark formed on the valve stud and a movable mark formed on the crosshead. Fixing consists landmarks were injection device is obtained which is characterized by having a resin passage position display means for displaying an amount of deviation from the normal angular position relative to the crosshead of the delivery and injection modes when the valve stud.

According to the present invention, there is also obtained the injection device in which the movable mark and the fixed mark are formed at a radius position as large as possible about the center of rotation of the valve stud.

According to the present invention, there is further provided the injection apparatus having a resin passage position adjusting means for adjusting a detailed angular position of the valve stud between the crank mechanism and the expansion / contraction means.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an injection device according to an embodiment of the present invention will be described with reference to the drawings.

Referring to FIGS. 1 (a) and 1 (b) and FIG. 2 (partial side view indicated by arrow A in FIG. 1 (a)), a pre-plastic injection apparatus according to an embodiment of the present invention is described. 4 and FIGS. 5 (a) and 5 (b), a pre-plaster cylinder (not shown) for melting and feeding the resin, and a nozzle 40 connectable to a mold set in the injection molding machine. An injection cylinder section 20 for injecting a predetermined amount of resin from the pre-plastic cylinder section through the nozzle 40
And a rotary path switching unit.

The rotary path switching section has a substantially T-shaped cross section, and each path has a pre-plastic cylinder section and an injection cylinder section 2 respectively.
0, a resin passage facing the nozzle 40, and a crosshead 31 having a space section having a circular cross section centered on the intersection thereof, and a resin passage having a substantially T-shaped cross section provided rotatably in the circular space section of the crosshead. And a hydraulic cylinder 33 fixed to the crosshead 31 via a base plate 33g and rotationally driving the valve stud 32 via a crank mechanism. In a resin feeding mode, a pre-plastic cylinder unit and an injection cylinder are injected. Cylinder section 20
While the valve stud 32 communicates with
In the injection mode for injecting resin, the injection cylinder section 20 is made into a chamber independent of the pre-plastic cylinder section by the valve stud 32, and the inside of the injection cylinder section 20 and the nozzle 40
The resin path is switched so as to communicate with.

Now, the injection device is provided with a valve stud 32.
A stud pointer 34c, which is a movable mark fixed to the side surface of the valve stud 32, as a resin passage position display means for displaying the amount of deviation from the normal angular position with respect to the crosshead 31 in each mode of sending and injecting.
1 has a position mark 34a at the time of delivery and a position mark 34b at the time of injection, which are fixed marks. On the end face of the valve stud 32, a resin flow path display portion 34d for displaying the direction in which the resin flows is formed.

The hole for mounting the stud pointer 34c, the position scale 34a at the time of delivery and the position scale 34b at the time of injection are formed precisely at the time of manufacturing the valve stud 32 and the crosshead 31, respectively.
Reference numeral 4c denotes a material and a shape that are hardly warped or deformed, have excellent display accuracy, and do not change with time.

When the stud pointer 34c is at the position scale 34 at the time of transmission.
When the pointer a is pointing, the stud pointer 34c is pointing at the injection position scale 34b, and the valve stud 32 is at a regular angular position with respect to the crosshead 31, and there is no step in the resin flow path. is there. In this manner, without performing any disassembly work such as removing the pre-plastic cylinder unit or the injection cylinder unit 20 from the crosshead 31,
The angular position of the valve stud 32 with respect to the crosshead 31 in each of the modes of sending and injecting the valve stud 32 and the stepped state of the resin flow path can be visually confirmed with high accuracy.

The stud pointer 34c, the delivery position scale 34a and the injection position scale 34b are formed at as large a radius position as possible about the center of rotation of the valve stud 32. Thus, even if the valve stud 32 is slightly misaligned, the stud pointer 34c moves a large arc distance, so that the amount of angular misalignment can be known with higher accuracy. For example, assuming that the cross-sectional radius of the valve stud 32 is Rbs and the radius drawn by the tip of the stud pointer 34c at the time of rotation is Rsi, the amount of angular deviation can be confirmed with Rsi / Rbs times accuracy.

The injection apparatus also has a resin passage position adjusting means for adjusting the detailed angular position of the valve stud 32 between the crank mechanism and the hydraulic cylinder 33. Specifically, the hydraulic cylinder 33 is
a, piston rod 33b, and telescopic end stopper 33
The crank mechanism includes an injection position adjustment screw 33c, a delivery position adjustment screw 33d, and a connection link 33e. Then, referring to the angular position of the valve stud 32 using the resin passage position display means described above, first, the piston rod 3 of the hydraulic cylinder 33 is used.
3b is extended, and the position adjusting screw 33d at the time of sending is rotated to set the stud pointer 34c to the position scale 34a at the time of sending.
To guide them. Next, with the piston rod 33b of the hydraulic cylinder 33 contracted, the injection position adjusting screw 33c is applied to the expansion / contraction limit stopper 33f, the injection position adjusting screw 33c is rotated, and the stud pointer 34c is set to the injection position scale 34b. To guide them. The hydraulic cylinder 33 is a general-purpose hydraulic cylinder defined by the JIS standard and has a total length of ± 1.6 mm, a stroke of +0.8,
Although there is a dimensional tolerance of −0.0 mm, that is, a dimensional variation among individual products, it can be solved by initial adjustment using a resin passage position adjusting means.

FIG. 3 is a perspective view showing a main part of another example of the injection apparatus according to the present invention. Referring to FIG. 3, in this example, the crosshead 3 is used as a resin passage position display means for displaying the amount of deviation from the normal angle position with respect to the crosshead 31 in each mode of sending and injecting the valve stud 32.
The stud pointer 34c ', which is a movable mark fixed to the valve stud 32 exposed on the side of the crank mechanism 1, and the base plate 33g fixed on the side of the crosshead 31 on the side of the crank mechanism are formed on the plate surface. It also has a position mark 34a 'for sending and a position mark 34b' for injection, which are fixed marks.

In this embodiment, since the resin passage position display means is formed on the same side as the crank mechanism, that is, on the same side as the resin passage position adjustment means, the resin passage position is visually checked while the angular position of the valve stud 32 is visually confirmed. The work of adjusting using the adjusting means can be executed by one worker.

In the present invention, the resin passage position display means may be constituted by a plurality of movable marks (all movable marks move together) and a single fixed mark.

[0030]

The injection device according to the present invention comprises a movable mark formed on the valve stud and a fixed mark formed on the crosshead. The injection device from the regular angular position with respect to the crosshead in each mode of sending and ejecting the valve stud. Since there is a resin passage position display means for displaying the amount of displacement, it is not necessary to perform extensive removal work of each member such as the pre-plastic cylinder section and the injection cylinder section. Since the adjustment can be performed while visually checking, the adjustment of the resin passage can be performed easily and with high accuracy, which is useful for obtaining a good molded product.

[Brief description of the drawings]

1 (a) and 1 (b) are a top view and a side view showing an injection device according to an embodiment of the present invention.

FIG. 2 is a partial side view of the injection device shown in FIG.

FIG. 3 is a partial perspective view showing another example of the injection device according to the embodiment of the present invention.

FIG. 4 is a side view showing an injection device according to a conventional example.

5A and 5B are a cross-sectional view and a partial cross-sectional view of the injection device shown in FIG.

FIG. 6 is an enlarged sectional view of a part of the injection device shown in FIG.

[Explanation of symbols]

 20, 120 Injection cylinder part 130 Rotary path switching part 31, 131 Cross head 32, 132 Valve stud 33, 133 Hydraulic cylinder 33a Cylinder 33b Piston rod 33c Position adjustment screw 33d for injection Position adjustment screw 33d for delivery 33e Connection link 33f Expansion / contraction limit stopper 33g Base plate 34a, 34a 'Position scale 34b, 34b' for injection Position scale 34c, 34c 'for injection Stud pointer 34d Resin flow path indicator 40, 140 Nozzle

Claims (3)

(57) [Claims] 1. A pre-plastic cylinder section for melting and feeding resin, a nozzle connectable to a mold set in an injection molding machine, and an injection cylinder for injecting a predetermined amount of resin from the pre-plastic cylinder section through the nozzle. Part and section T
A crosshead having a space portion having a circular cross section centered on the resin passage and the intersection thereof, each of which has a letter shape and each path faces the pre-plastic cylinder portion, the injection cylinder portion, and the nozzle, respectively, and a circular space portion of the crosshead. In a pre-plastic injection device having a valve stud rotatably provided and having a resin passage having a substantially T-shaped cross section and expansion and contraction means for rotating the valve stud through a crank mechanism, the valve stud is formed on the valve stud. And a resin passage position display means for displaying the amount of deviation from the normal angular position with respect to the crosshead in each mode of sending and injecting the valve stud, the movable mark being provided and a fixed mark formed on the crosshead. An injection device characterized by the above-mentioned. 2. The injection apparatus according to claim 1, wherein the movable mark and the fixed mark are formed at a radial position as large as possible about a center of rotation of the valve stud. 3. The injection apparatus according to claim 1, further comprising a resin passage position adjusting means for adjusting a detailed angular position of the valve stud between the crank mechanism and the expansion / contraction means.