JP7384944B2 - Injection equipment for die casting - Google Patents

Description

The present invention relates to an injection device for die casting.

BACKGROUND ART Conventionally, a die-casting injection device is known that includes a plunger tip that is movably provided in a sleeve that supplies molten metal into a mold cavity (see, for example, Patent Document 1). The plunger tip is screwed onto the tip of the plunger rod, and the plunger rod is connected to the piston rod of the injection cylinder via a coupling.

JP2011-92968A

If the piston rod is pushed out and the plunger tip is in contact with the molten metal in the cavity, the plunger tip may not be able to rotate due to the frictional resistance between it and the molten metal. The screws may become loose. In this case, it is necessary to frequently check the threaded state of the plunger tip and plunger rod, which makes maintenance troublesome.

In Patent Document 1, a notch is formed in the plunger rod to position the center of gravity of the plunger rod downward, thereby making it difficult for the plunger rod to rotate. However, it is not necessary to form a notch in the plunger rod. Therefore, manufacturing costs increase.

In view of the above points, an object of the present invention is to provide a die casting injection device that can suppress loosening of the screw connection between a plunger tip and a plunger rod without forming a notch in the plunger rod. .

In order to achieve the above object, the die casting injection device of the present invention has the following features:
an injection cylinder having a piston rod;
a plunger rod connected to the piston rod;
two cooling water ports that are provided on the plunger rod in parallel in the central axis direction of the plunger rod and that are visible at the same time when viewed from the opening side of the cooling water port;
a plunger tip screwed onto the tip of the plunger rod and disposed within the sleeve;
Two cooling water hoses for circulating cooling water within the plunger rod are connected to the plunger rod via the cooling water port ,
In a die casting injection device for injecting molten metal supplied into the sleeve into a mold cavity by the plunger tip,
The cooling water hose is configured such that only a load is applied to the plunger rod in a tightening direction in which the threaded engagement with the plunger tip is tightened with respect to the plunger rod in the forward position where the molten metal is injected by the plunger tip. It is characterized by being located in.

According to the present invention, when the plunger rod is located in the forward position, the circumferential pressing force or tensile force applied to the plunger rod by the cooling water hose is applied to the plunger tip, which cannot be rotated by the plunger rod and the molten metal. A tightening force is applied to strengthen the screw connection. Therefore, according to the present invention, loosening of the screw engagement between the plunger tip and the plunger rod can be suppressed without forming a notch in the plunger rod.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a die-casting mold in which a die-casting injection device according to an embodiment of the invention is used. FIG. 2 is an explanatory diagram schematically showing a die-casting injection device according to an example of the present embodiment with a plunger rod located at a forward position. FIG. 7 is an explanatory diagram schematically showing a die-casting injection device according to another example of the present embodiment with the plunger rod located in the forward position.

A die casting injection device according to an embodiment of the invention will be described with reference to the drawings. A die-casting injection device 1 of this embodiment is used for a die-casting mold 10 shown in FIG. The die casting mold 10 includes a fixed mold 11 and a movable mold 12. The fixed mold 11 is provided with a sleeve 14 for supplying molten metal into a mold cavity 13 defined by the fixed mold 11 and the movable mold 12. The tip of the die casting injection device 1 of this embodiment is inserted into this sleeve 14.

Referring to FIG. 2, the injection device 1 for die casting according to the present embodiment includes an injection cylinder (not shown) in which a piston rod 2 can move forward and backward, and a plunger rod 4 connected to the piston rod 2 via a coupling 3. Cooling water is circulated within the plunger rod 4 through a plunger tip 5 screwed onto the tip of the plunger rod 4 and disposed within the sleeve 14, and two cooling water ports 6 provided on the plunger rod 4. It is equipped with two cooling water hoses 7 for use.

The die casting injection device 1 can inject the molten metal supplied into the sleeve 14 into the mold cavity 13 using the plunger tip 5 by moving the piston rod 2 forward and backward using an injection cylinder (not shown).

Here, when the piston rod 2 is pushed out and the plunger tip 5 is in contact with the molten metal in the mold cavity 13, the plunger tip 5 may not be able to rotate due to the frictional resistance between it and the molten metal. When the plunger rod 4 rotates, the threaded engagement with the plunger tip 5 may become loose depending on the direction of rotation. In this case, it is necessary to frequently check the threaded state of the plunger tip 5 and the plunger rod 4, which makes maintenance troublesome.

Therefore, in the die casting injection device 1 of this embodiment, when the plunger tip 5 is located at the forward position where the piston rod 2 is pushed forward so that the molten metal is injected by the plunger tip 5, In this case, the cooling water hose 7 is arranged so that a load is applied to the plunger rod 4 in the tightening direction in which the plunger tip 5 is tightened with respect to the plunger rod 4.

For example, referring to FIG. 2, suppose that the cooling water port 6 protrudes laterally from the plunger rod 4, and furthermore, the plunger rod 4 is moved in the circumferential direction so that the cooling water port 6 moves downward from this state. Assume that when the plunger tip 5 rotates, the threaded engagement between the plunger tip 5 and the plunger rod 4, which are prevented from rotating by the molten metal, is tightened. In this case, the cooling water hose 7 is arranged so that the cooling water port 6 is pulled downward by the cooling water hose 7 in the forward position.

As a result, in the forward position where the plunger tip 5 is prevented from rotating, a rotational force in the tightening direction is applied to the plunger rod 4 by the cooling water hose 7, so that the plunger rod 4 and the plunger tip 5 are not screwed together. Loosening can be prevented or suppressed. Note that when the plunger rod 4 is not in the forward position, the plunger tip 5 is not in contact with the molten metal, so the plunger tip 5 rotates together with the plunger rod 4, and the screw connection does not loosen. .

As another example, referring to FIG. 3, suppose that the cooling water port 6 protrudes laterally from the plunger rod 4, and furthermore, the plunger rod 4 is moved so that the cooling water port 6 moves upward from this state. Assume that when the plunger tip 5 rotates in the circumferential direction, the threaded engagement between the plunger tip 5, which is prevented from rotating by the molten metal, and the plunger rod 4 is tightened. In this case, in the forward position, the cooling water hose 7 is compressed in the vertical direction so that the cooling water port 6 is pushed upward by the cooling water hose 7.

As a result, in the forward position where the plunger tip 5 is prevented from rotating, a rotational force in the tightening direction is applied to the plunger rod 4 by the cooling water hose 7, so that the plunger rod 4 and the plunger tip 5 are not screwed together. Loosening can be prevented or suppressed.

In addition, in the two examples mentioned above, it is assumed that the cooling water supply source is located below the plunger rod 4, so when lowering the cooling water port 6, the cooling water hose 7 It was explained that the cooling water hose 7 is used to pull it up, and when it is lifted upward, it is pushed up using the cooling water hose 7. However, if the cooling water supply source is located above the plunger rod 4, when lowering the cooling water port 6, the cooling water hose 7 is used to push it down, and when raising it upward, the cooling water The cooling water hose 7 may be arranged so as to be pulled by the water hose 7.

1 Injection device for die casting 2 Piston rod 3 Coupling 4 Plunger rod 5 Plunger tip 6 Cooling water port 7 Cooling water hose 10 Die casting mold 11 Fixed mold 12 Movable mold 13 Mold cavity 14 Sleeve

Claims (1)

an injection cylinder having a piston rod;
a plunger rod connected to the piston rod;
two cooling water ports that are provided on the plunger rod in parallel in the central axis direction of the plunger rod and that are visible at the same time when viewed from the opening side of the cooling water port;
a plunger tip screwed onto the tip of the plunger rod and disposed within the sleeve;
Two cooling water hoses for circulating cooling water within the plunger rod are connected to the plunger rod via the cooling water port ,
In a die casting injection device for injecting molten metal supplied into the sleeve into a mold cavity by the plunger tip,
The cooling water hose is configured such that only a load is applied to the plunger rod in a tightening direction in which the threaded engagement with the plunger tip is tightened with respect to the plunger rod in the forward position where the molten metal is injected by the plunger tip. An injection device for die casting, characterized in that the injection device is arranged in a.

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