JPH0221345B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an injection device for a die-casting machine,
More specifically, the present invention relates to an injection device for a die-casting machine that has an improved mounting structure for an injection cylinder and the like.

The injection device of a die-casting machine is constructed around an injection cylinder, which is mounted facing a fixed platen.

FIG. 1 shows the mounting structure of a conventional injection device.

In FIG. 1, the reference numeral 1 indicates a solid stationary platen, and on the surface of the stationary platen 1 opposite to the side on which the stationary mold 1a is attached, there is an injection frame 2 having a U-shaped cross section, for example. It is fixed by bolts 3, 3, and an injection cylinder 4 is fixed to this injection frame 2. The injection cylinder 4 has a coupling ring 5
It has an injection plunger 5 via a, and the tip of the injection plunger 5 is slidably fitted into an injection sleeve 6 provided on the fixed platen 1 side. An opening 6a for supplying molten metal is provided in the middle of the injection sleeve 6.
As the injection plunger 5 moves forward due to the operation of the injection cylinder 4, the molten metal supplied from a is brought into the mold cavity formed at the mating surface of the fixed mold 1a and a movable mold (not shown) to a predetermined pressure. The injection product is then molded.

However, if such a structure is adopted, since the injection frame 2 is separate from the fixed platen 1, the centering of the injection cylinder 4 will be extremely difficult unless the mounting accuracy of the injection frame 2 to the fixed platen 1 is maintained at a high level of accuracy. Moreover, the injection frame 2 must be constructed separately from the stationary platen 1 and have a strong structure, which increases the weight and is extremely disadvantageous in terms of installation work and deterioration over time.

In addition, in the conventional device, the stationary platen 1 has to be made thick in order to obtain the necessary rigidity, and therefore, the position of the hot water supply port 6a provided in the injection sleeve 6 is relatively rearward, so the injection sleeve 6 In addition to the length of the injection plunger 5 and the injection cylinder 4,
The stroke of the device also became longer, and the device as a whole became longer.

Furthermore, if the position of the hot water supply port 6a is at the rear and the injection sleeve 6 is lengthened, when a certain amount of molten metal is put into the injection sleeve 6, the height of the molten metal in the injection sleeve 6 will be lowered, and the molten metal will be filled up. As a result, the molten metal inside the injection sleeve 6 cools down easily, and the thin, solidified molten metal on the inner surface of the injection sleeve 6 easily enters the mold, making it difficult to produce good injection products. Ta. In addition, the molten metal has a larger contact area with air, which makes it easier for air to be trapped during injection, making it easier to produce injection products with cavities.

The present invention has been made to solve the above-mentioned conventional drawbacks, and has a structure that allows centering to be performed extremely easily, reduces weight, and increases strength. By making the mold attachment part relatively thin and shortening the length of the injection sleeve, the equipment can be made more compact, injection can be performed under better conditions, and work around the equipment can be reduced. The purpose of this invention is to provide an injection device for a die casting machine that is easy to use.

In the present invention, the fixed plate part to which the fixed mold and the injection sleeve are attached, and the hollow injection frame part to which the injection cylinder is attached are integrally constructed, and each member is made into a strength member. The structure is designed to increase specific rigidity, and a window is provided in the injection frame. Then, a support member is provided at the lower part of the injection cylinder mounting side of this injection frame part, and the lower surface of the fixed platen part is mounted on the machine base.
The support member provided on the injection frame portion was placed and held on a support frame provided on the floor.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

2 to 4 show one embodiment of the present invention,
Components that are the same as those shown in FIG. 1 are designated by the same reference numerals, and their explanation will be omitted. In this embodiment, the mold mounting part, which is a part of the stationary platen, and the injection frame part 2 are formed into an integral frame 20, which has a hollow structure as a whole. The hollow injection frame 2 is provided with several axial ribs 7 to maintain its strength.

An injection cylinder 4 is fixed to the rear edge of the injection frame 2, and an injection sleeve 6 is attached to a relatively thin stationary plate 1. 6a is a hot water supply port provided in the injection sleeve 6. This device has a hollow structure as a whole, so
Since the 1st part of the fixed platen can also be made thinner, the length of the injection sleeve 6 can be shortened to improve casting conditions as described later, and the 2nd part of the injection frame is integrally constructed with the 1st part of the fixed platen. Therefore, there is no need to attach it to the fixed platen 1 using bolts, etc., and only centering is required when installing the injection cylinder 4, and there is no need for centering when installing the injection frame 2 as in the past. becomes.

On the other hand, although the injection frame 2 is formed hollow, since it is necessary to supply molten metal, an opening 8 for molten metal supply is formed in the side surface of the injection frame 2. However, although the opening 8 is one long opening in the illustrated example, it can also be formed into a plurality of openings. This allows the overall weight to be further reduced. Of course, the opening 8 is also useful when replacing or repairing the plunger tip at the tip of the injection plunger 5.

The shape and number of the openings 8 are determined in relation to the strength of the injection frame 2, the ribs 7, and the like.

A hanging hole 9 for attaching or removing the injection plunger 5, etc. is provided in the upper center of the injection frame 2.
A discharge hole 10 is provided at the center of the lower part of the tube for discharging scale and the like generated during injection.

Flange-shaped support members 11 are provided on both sides in the lateral direction at the lower part of the injection frame 2 on the side where the injection cylinder 4 is attached. and is held by bolts 14. Note that the lower surface of the stationary platen 1 is fixed to an end on the machine base 15 with bolts 16.

Note that 17 is a column and 18 is a column nut.

Next, the differences in how the mold mounting member flexes between the present invention and a conventional device will be conceptually compared and compared.

FIG. 5 is a diagram showing the deflection state of one part of the fixed platen, that is, the mold mounting part in the present invention as shown in FIGS. 2 to 4, and FIG. It is a figure which shows the bending state of the stationary platen 1 in .

In FIGS. 5 and 6, solid lines each indicate the case where no load w is applied, and dotted lines each indicate the deformed state when the load w is applied.

In addition, in the formula below, L and L' are the lengths between the supporting points that receive the load w, T is the thickness of the fixed plate 1 part and the fixed plate 1, and w is the unit that acts on the fixed plate 1 part and the fixed plate 1. The length load, δa, δa′, δb, and δα are the amount of deflection of each part shown in the figure, E is Young's modulus, I is the moment of inertia of area, and R is the radius of the curved surface of the opening hole 8.

As shown in FIG. 5, in the case of the present invention, the fixed platen 1
Since the injection frame 2 and the injection frame 2 are integrated, it can be seen as a fixed end support, and the deflection is very complicated, but since the injection frame 2 and the rib 7 have very small deflections, the deflection δa is approximately expressed by the following equation.

δa≒wL ⁴ /384EI ...(1) However, in reality, considering the structure of the two parts of the injection frame, the fulcrum is placed inside, and L' can be designed to be smaller than L, so the deflection δa The value of becomes even smaller. As an example, if the fulcrum is assumed to be at the end of the hole 8 and L'=0.7L, then the deflection δ'a is given by the following equation.

δ′a≒w(L′) ⁴ ／384EI＝0.2401wL ⁴ ／384EI……
(2) On the other hand, in the case of the conventional device as shown in Fig. 6, the fixed platen 1 and the injection frame 2 are separate bodies, and the fixed platen 1 seems to support the free end. The deflection δb is expressed by the following formula.

δb=5wL ⁴ /384EI ...(3) Comparing these, the amount of deflection when L'=L and no R part is 1/5 of the conventional one, L'=0.7L, and furthermore, including the R part, the amount of deflection is 1/5 of the conventional one. In this case, the amount of deflection will be 1/20 to 1/30 of the conventional one, and the deflection will be extremely small. Of course, the rigidity increases accordingly.

According to the present invention, since the stationary platen 1 hardly bends, the rear edge of the injection frame 2 does not lower with each injection operation. Therefore, the support member 11 can be fixed to the support frame 13 with the bolts 14.

In contrast, as in conventional devices, the fixed platen 1 is bent for each injection operation, and the injection frame 2 is bent.
If the device has a trailing edge that moves downward, it is necessary to support the lower part of the trailing edge of the injection frame 2 from below, and for this purpose it is necessary to provide a counterbalance device such as a disc spring or a fluid pressure cylinder. However, in the present invention, there is no need to provide such an extra device, and the rear edge of the injection frame 2 can be fixed to the support frame 13 as described above.

On the other hand, as in the present invention, if the mold attachment part of the stationary platen 1 becomes thinner and the hot water supply port 6a of the injection sleeve 6 is moved forward by that amount, the injection apparatus as a whole can be made thinner. It will be three times shorter. This state is shown in FIG. Figure 7a shows a conventional device;
FIG. 7b shows the case of the present invention. In the figure, S
is the distance at which the mold mounting surface of the stationary platen 1 becomes thinner and the hot water supply port 6a of the injection sleeve 6 protrudes forward. In addition, in the figure, the forward limit position of the injection plunger 5 is shown by a two-dot chain line.

When the hot water supply port 6a of the injection sleeve 6 moves forward by an amount S, the hot water supply port 6a moves forward from the forward limit position of the injection plunger 5.
The distance A to a, that is, the injection stroke, can be shortened by that amount S, and the distance B from the rear end of the injection sleeve 6 to the coupling ring 5a provided at the rear of the injection plunger 5 and the length of the injection plunger 5 can also be shortened by S. Moreover, the injection stroke C of the injection cylinder 4 is also shortened by S, and the length of the injection cylinder 4 can also be shortened by S. That is, since each of A, B, and C can be made shorter by S, the injection device as a whole becomes shorter by 3S.
As the equipment space becomes smaller,
This is extremely advantageous in manufacturing, mounting, and operating the device.

For example, in the case of die casting with a mold clamping force of 330 tons, the thickness of the mold mounting part of the fixed plate 1 is conventionally 220 tons.
According to the present invention, for example,
It was possible to make it 100mm.

If the injection sleeve 6 is shortened as in the present invention, when the same amount of molten metal is supplied into the injection sleeve 6, the filling rate of the molten metal into the injection sleeve 6 will improve, and the molten metal surface will rise. The surface area of the molten metal cooled in the sleeve 6 is reduced, the heat retention of the molten metal is increased, and injection can be performed under good temperature and flow conditions. There is less of the shell trying to harden and less of it getting into the mold. Furthermore, since the area in which the molten metal is in contact with air within the injection sleeve 6 is reduced, the amount of gas involved is reduced. Therefore, it becomes easier to obtain a good injection product with fewer cavities.

In this way, the central part of the stationary platen 1 to which the injection sleeve 6 is attached should originally be made as thin as possible, but with the present invention, it is possible to make that part thinner by making it resistant to bending.

As described above, in the present invention, the fixed mold and the injection frame portion to which the injection sleeve is attached are constructed as a hollow integral structure, and each member is made into a strength member, thereby making it easier to attach the mold. Since the structure increases the specific rigidity of the parts, the overall wall thickness can be made thinner.In particular, the mold attachment part of the fixed platen 1 can be made considerably thinner than the conventional fixed platen 1, which reduces the weight. In addition to being able to reduce the amount of damage, the overall rigidity and strength can also be increased, and deflection can be significantly reduced. Further, by adopting the integral structure, centering work of the injection frame portion during assembly becomes unnecessary, and centering work of the injection cylinder becomes extremely easy.

In addition, the length of the injection sleeve can be shortened, making the entire device more compact and easy to manufacture.The installation space is also reduced, making it easier to operate around the device. The casting conditions can be improved to allow injection under certain conditions. Therefore, it is possible to reliably and easily obtain a good injection product with good hot water flow and molding condition, and no cavities.

Additionally, a window is provided in the injection frame, making work easier. That is, if an opening is provided in the side surface of the injection frame, hot water can be easily supplied to the injection sleeve through the opening, and the plunger tip, injection plunger, etc. can be easily replaced. In addition, if a hole is provided at the top of the injection frame, it can be used as a hanging hole when replacing an injection plunger, etc., and if a hole is provided at the bottom of the injection frame, aluminum powder generated during injection can be removed. It can be used as a discharge hole for scales such as small lumps.

In addition, a support member is provided at the lower part of the rear edge of the injection frame on the side where the injection cylinder is attached.
Even if the injection device becomes larger and the injection frame portion becomes larger, the injection frame portion can be sufficiently supported to eliminate core twisting, and the fixed plate portion can be easily attached. In conventional equipment, the stationary plate flexes with each injection operation, and the trailing edge of the injection frame goes down. Although it was necessary to provide a counterbalance device such as a liquid pressure cylinder, in the present invention, the fixed platen hardly bends during each injection operation, and the trailing edge of the injection frame section Since the part does not fall down, there is no need to provide extra equipment as described above, and the support member can be fixed to the support frame with bolts, etc., and the rear edge of the injection frame part can be securely held. This allows a good injection operation to be performed every time without any core twisting between the injection cylinder and the injection sleeve during the injection operation, and without applying excessive force to each member.

Of course, if a rib is provided on the injection frame,
Becomes more sturdy.

[Brief explanation of drawings]

Fig. 1 is a front view showing an example of a conventional device similar to the present invention, Figs. 2 to 4 show an embodiment of the present invention, Fig. 2 is a front view, and Fig. 3 is a longitudinal section. 4 is a plan view, FIG. 5 is a diagram showing the deflection state of the fixed platen part in the present invention, FIG. 6 is a diagram showing the deflection state of the fixed platen in the conventional device, and FIGS. 7a and 7b are FIG. 3 is a schematic vertical cross-sectional view showing a comparison of the difference in length of the injection device section between the present invention and a conventional device, respectively. DESCRIPTION OF SYMBOLS 1... Fixed plate, 1a... Fixed mold, 2... Injection frame, 4... Injection cylinder, 5... Injection plunger, 6... Injection sleeve, 7... Rib, 8...
...opening, 9...hanging hole, 10...discharge hole, 11
...Support member, 13...Support frame, 15...
Machine base, 20...frame.

Claims (1)

[Claims] 1. By making the fixed plate part to which the fixed mold and the injection sleeve are attached, and the hollow injection frame part to which the injection cylinder is attached, a completely integrated structure, and making each member a strength member, The mold mounting part has a structure that increases the specific rigidity, a window is provided in the injection frame part, a support member is provided at the bottom of the injection frame part on the side where the injection cylinder is mounted, and the lower surface of the fixed plate part is mounted on the machine base. Also, an injection device for a die-casting machine, in which the support member provided on the injection frame portion is mounted on and held on a support frame provided on a floor surface.