JPH0321814Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a die-casting machine, especially a horizontal injection cold chamber type die-casting machine, in which molten aluminum or other metals supplied into an injection sleeve is used to cool the mold. The present invention relates to a plunger chip that is injected into a cavity, and relates to an improvement of a plunger chip equipped with a cooling mechanism for preventing the occurrence of flash between the outer peripheral surface of the chip and the inner peripheral surface of a sleeve.

<Prior art> In general, horizontal horizontal injection cold chamber type die casting involves inserting a plunger tip into an injection sleeve installed horizontally so as to reciprocate back and forth, and the forward movement of this tip causes the injection sleeve to The structure is such that the molten metal supplied inside is injected and filled into the cavity of the mold. Therefore, since the plunger tip is heated by direct contact with high-temperature molten metal, it is necessary to provide a clearance between the outer circumferential surface of the tip and the inner circumferential surface of the injection sleeve, taking into account the thermal expansion of the tip. .

However, setting this clearance is difficult due to various conditions such as the casting conditions of the die casting machine and the temperature of the lubricating oil applied to the outside of the plunger tip, and molten metal may enter this clearance. Therefore, it was inevitable that casting burrs would occur. Furthermore, in this type of horizontal horizontal injection cold chamber type die casting machine, the lower part of the plunger tip is in contact with the molten metal for a longer time than the upper part, resulting in a temperature difference, and the lower part experiences thermal expansion. becomes large. Therefore, as the number of casting shots increases, the temperature difference between the upper and lower parts of the chip becomes constant, and burrs are more likely to occur on the upper part of the chip, where thermal expansion is small, and uneven wear occurs. Furthermore, if burrs occur between the plunger tip and the injection sleeve, it will cause seizing or galling between the two, which not only accelerates the wear and tear of both, but also becomes a major cause of malfunction of the plunger tip. Due to this malfunction, the molten metal is not reliably injected into the mold cavity, which adversely affects the quality of the product.

Therefore, in order to alleviate the thermal expansion of the plunger chip, cooling water is passed inside the chip to cool the chip itself, thereby setting the clearance between it and the injection sleeve as small as possible and preventing the occurrence of flash. Plunger chips have been devised and provided with the aim of achieving this. For example, a plunger chip of the structure shown in FIG. 5 exists.

The plunger tip A' forms a cooling chamber 2' through which cooling water flows, and communicates with the cooling water passage 1 formed in the rod B by being connected to the tip of the rod B of the injection cylinder. This is to reduce thermal expansion.

However, this conventional plunger tip
Since the entire chip A′ is directly cooled by cooling water, the entire temperature range of chip A′ will be excessively cooled, and the intrusion of molten metal will be prevented using thermal expansion at the desired time. However, it cannot be said that it is effective in preventing the occurrence of cast burrs, and if the molten metal that has been supplied into the injection sleeve is injected in this state, a part of the molten metal will enter and the generation of cast burrs will increase. It was not the best cooling structure as it easily led to the opposite effect.

In addition, since the entire attachment of the injection cylinder to the tip of rod B is rigid, the plunger tip has a long contact time with the molten metal and has large thermal expansion.
The lower side of A′ suffers more wear due to thermal effects than the upper side, which has a smaller thermal expansion, resulting in uneven wear, which significantly shortens the life of the chip, making it unsatisfactory for long-term use. The desired results were not obtained.

<Problems to be solved by the invention> The problems to be solved by the invention are to prevent an excessive drop in temperature of the entire plunger tip and to minimize the clearance between the outer circumferential surface of the tip and the inner circumferential surface of the sleeve. To provide a plunger tip which can be used for a long period of time by preventing the occurrence of cast burrs and preventing uneven wear (partial wear) due to repeated thermal effects.

<Means for solving the problem> The technical means taken by the present invention to solve the above problem is to connect the chip body to the tip of the rod of the injection cylinder by communicating with the cooling water flow passage in the rod. It is composed of a main body and a sliding outer cylinder that is rotatably fitted and attached to the outside of the main body. At the same time as forming the thread part of
A cooling chamber is formed from the end surface of the threaded portion toward the vicinity of the other end of the main body through a cooling water communication path that communicates with the cooling water flow path. It is formed into a hollow cylindrical shape whose inner diameter and outer diameter are substantially the same as the outer diameter of the main body, and is rotatably inserted into the outside of the main body.

<Function> In the present invention, the rod is screwed onto the tip of the injection cylinder via the threaded portion at one end, so that the rod is rigidly attached and supported by the tip of the rod, and communicates with the cooling water flow passage within the rod. The main body is cooled by supplying cooling water to the cooling chamber inside the main body, and the sliding outer cylinder is attached to the outside of the main body by heat transfer from the main body directly cooled by the cooling water. As a cooling structure that indirectly cools the chip, it prevents an excessive drop in temperature of the sliding outer cylinder that slides against the inner peripheral surface of the injection sleeve, thereby reducing the temperature between the outer peripheral surface of the chip and the inner peripheral surface of the sleeve. Keep clearance to a minimum,
This aims to prevent the occurrence of cast burrs caused by the intrusion of a portion of the molten metal. The outer circumferential surface of the tip relative to the inner circumferential surface of the sleeve occurs due to the mouth shape of the injection sleeve itself which deforms when exposed to molten metal, and the misalignment between the axial center of the injection sleeve and the axial center of the plunger tip. Due to the contact position shift phenomenon, the sliding contact outer cylinder rotatably attached to the main body is moved at a desired time, that is, when molten metal is injected or when retreating as the molten metal injected into the cavity finishes solidifying. The plunger tip is rotated when it moves back and forth, thereby preventing uneven wear (partial wear) of the tip's outer circumferential surface due to repeated heat effects from molten metal, thereby enabling long-term use.

<Example> An example of the present invention will be described based on the drawings.
The chip main body A has a main body part _a1 connected and supported at the tip of the rod B of the injection cylinder, which communicates with the cooling water flow passage 1 in the rod B, and a main body part A1 that is rotatably inserted into the outside of the main body part _A1 . It is composed of a sliding outer cylinder _a2 that is brought into sliding contact along the inner circumferential surface of the injection sleeve C, and is inserted into the injection sleeve C so as to reciprocate back and forth.

The main body part _A1 is connected and supported in a rigid state to the tip of the rod B, and is directly cooled by the cooling water supplied to the inside communicating with the cooling water flow passage 1 in the rod B, and comes into contact with the molten metal. This is for indirectly cooling the outer cylinder a ₂ by transmitting heat to the sliding contact outer cylinder a ₂ whose temperature has increased, and includes an outer cylinder mounting member 101 into which the outer cylinder a ₂ is inserted and mounted, and Joining member 10 to member 101
2, and a connecting member 103 that connects the other end to the tip of the rod B, thereby forming the rod B into a desired length.

The outer cylinder mounting member 101 has an outer diameter attached to the injection sleeve B.
It is formed into a solid rod shape with a smaller diameter than the inner diameter of the rod, and a cooling chamber 2 of a desired size is recessed in the axis from one end face to the vicinity of the other end face, and an outer cylinder engagement member is provided on the outer peripheral edge of the other end face. A locking flange 3 is provided around the same body in a protruding manner.

Further, a locking groove 4 having a desired groove width is formed in a ring shape on the outer circumferential surface near one end surface of the outer cylinder mounting member 101, so that the joining member 102 is fitted and locked therein.

On the other hand, the connecting member 103 is formed in the shape of a solid rod having the same outer diameter as the outer cylinder mounting member 101, and a threaded portion 5 for connecting the rod B is formed at one end thereof.
A fitting part 6 is formed at the other end to be inserted and fitted closely into the opening of the cooling chamber 2.
A cooling water communication path 7 for communicating the cooling water flow path 1 in the rod B with the cooling chamber 2 in the outer cylinder mounting member 101 is bored in the axis extending from the end surface of the rod B to the end surface of the screw portion 5.

Further, the outer cylinder mounting member 101 is attached to the outer circumferential surface near the fitting portion 6 formed at the other end of the connecting member 103.
A locking groove 8 having the same width as the locking groove 4 is formed to similarly fit and lock the joining member 102, and the outer peripheral surface of the base of the threaded portion 5 adjacent to the locking groove 8 is provided with a spanner or the like. A fastening part 9 for a tightening tool is formed protruding from the same body, so that the tightening tool can be used to screw the rod B into the tip.

Further, two parallel grooves 10 are provided on the outer peripheral surface of the fitting portion 6 of the connecting member 103, and the grooves 10 are provided with O.
The ring 11 is attached to prevent the cooling water supplied to the cooling chamber 2 in the outer cylinder mounting member 101 from leaking to the outside.

The joining member 102 has an inner diameter that is equal to or greater than the outer cylinder mounting member 1.
A pair of half bodies 12 and 13 are formed by cutting and dividing a cylindrical body having the same diameter as the outer diameter of 01 and the connecting member 103 in the cylindrical direction. Locking grooves 4, 8 of both members 101, 103
A fitting rib 14 for fitting and locking is formed protrudingly on the same body, and the abutting surface 1 of one half body 12 is formed on the same body.
2a is formed with a screw hole 15, and the other half body 13 is provided with a bolt insertion hole 16 that passes outward from the abutting surface 13a opposite to the screw hole 12a. The outer cylinder mounting member 101 and the connecting member 103 are joined together so as to be separable by tightening them with bolts 17.

The sliding outer cylinder _a2 has an outer diameter that is approximately the same as the inner diameter of the injection sleeve C, an inner diameter that is approximately the same as the outer diameter of the outer cylinder mounting member 101, and a length that is equal to the outer cylinder mounting member 101. It is formed into a hollow cylindrical shape that is slightly shorter than the length from the outer cylinder locking flange 3 to the locking groove 4, and is rotatably fitted onto the outside of the outer cylinder mounting member 101. In the figure, reference numeral 18 denotes a ring body that prevents the sliding outer cylinder a ₂ from coming into contact with the joining member 102 during the rotational movement of the sliding outer cylinder a ₂ .

Therefore, in this embodiment, after the outer cylinder A ₂ for sliding contact is inserted and attached to the outer cylinder device member 101, an O-ring 11 is inserted into the opening of the cooling chamber 2 of the outer cylinder mounting member 101.
The fitting portion 6 of the connecting member 103 is inserted and fitted to connect the two members 101, 103 in communication, and the pair of half bodies 12, 13 cross over the locking grooves 4, 8 of the members 101, 103. The chip main body A is constructed by fitting and mounting the bonding member 102 made of the above.

Then, using a tightening tool such as a wrench, the screw portion 5 of the connecting member 103 is attached and supported to the tip of the rod B, and the cooling water flow passage 1 in the rod B and the cooling inside the outer cylinder device member 101 are supported. It communicates with the chamber 2 through the cooling communication path 7 in the connecting member 103, so that cooling water is supplied from the cooling water flow path 1 in the rod B to the cooling chamber 2 in the outer cylinder mounting member 101. .

Therefore, in the chip body A, the outer tube mounting member 101 is once directly cooled by the cooling water supplied to the cooling chamber 2, and the outer tube mounting member 101 is cooled by heat transfer from the cooled outer tube device member 101. When the sliding outer cylinder _a2 attached to the member 101 is indirectly cooled, it becomes a cooling structure and the excessive temperature drop caused by the cooling water is alleviated. This prevents burrs from forming when molten metal enters the clearance between the two.

Chips on the inner circumferential surface of the sleeve occur due to the mouth shape of the injection sleeve C itself changing when exposed to molten metal, and the misalignment between the axis of the injection sleeve C and the axis of the chip body A that occurs at the same time. The sliding outer cylinder _A2 , which is rotatably attached to the outer circumferential surface due to the phenomenon of contact position displacement, is attached to the chip body when molten metal is injected or retreats as the molten metal injected into the cavity finishes solidifying. By rotating during the back-and-forth movement of A, it is possible to prevent uneven wear (partial wear) of the outer circumferential surface of the tip body A due to repeated heat effects from molten metal.
By simultaneously rotating the sliding outer cylinder _a2 ,
When the tip body A moves back and forth, the lubricating action acts to stabilize the movement of the tip body A.

In the above embodiment, the main body part _a1 constituting the chip main body is formed by an outer tube mounting member 101, a connecting member 103, and a joining member 102 that joins these two members 101, 103 in a separable manner. Although the outer cylinder mounting member 101 and the joining member 103 are formed as one piece connected to the same body, it is also optional.

<Effects of the invention> As mentioned above, the plunger tip of the present invention has a main body part that connects the tip body to the tip of the rod of the injection cylinder by communicating with the cooling water flow passage within the rod, and an outer part of the main body part. The body part is formed into a solid rod shape of a desired length, and a threaded part for connecting the rod is formed at one end of the main body part, and a threaded part for connecting the rod is formed at one end thereof. A cooling chamber is formed through a cooling water communication passage that communicates with the cooling flow passage in the axis extending from the end face of the part to the vicinity of the other end of the main body part, so that the cooling water supplied to the cooling chamber is The main body is directly cooled by water,
A cooling structure is created in which the sliding outer cylinder mounted on the outside is indirectly cooled by heat transfer from the directly cooled main body. Therefore, it is possible to reduce the excessive cooling of the entire chip, especially the sliding outer cylinder that is in sliding contact with the inner peripheral surface of the injection sleeve, and to minimize the clearance between the outer peripheral surface of the chip and the inner peripheral surface of the sleeve. Since the plunger tip can be held down to prevent molten metal from entering, it is possible to provide a plunger tip equipped with a cooling mechanism that can reliably prevent the occurrence of casting burrs.

In addition, a sliding contact outer cylinder formed in a hollow cylindrical shape whose inner diameter and outer diameter of the injection sleeve are approximately the same and whose inner diameter is approximately the same as the outer diameter of the main body is attached to the tip of the rod in a rigid state. Because it has a chip structure that is rotatably fitted to the outside of the main body that is mounted and supported,
The sliding outer cylinder rotates when the plunger tip moves back and forth during injection of molten metal or during retreat as the molten metal injected into the cavity finishes solidifying. This prevents uneven wear (partial wear) of the outer circumferential surface of the chip due to repeated heat effects from molten metal, thereby enabling long-term use.

Thus, the intended purpose can be achieved.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the plunger tip of the present invention, and FIG. 1 is a longitudinal sectional view showing the state in which it is attached and supported at the tip of the injection cylinder rod.
Figure 2 is a sectional view taken along the - line in Figure 1, and Figure 3 is a cross-sectional view of Figure 1.
4 is an exploded perspective view, and FIG. 5 is a longitudinal sectional front view showing a conventional example. In the figure, A: chip body, a ₁ : main body, a ₂ :
Sliding outer cylinder, B: Injection cylinder rod, 1:
Cooling water flow path, 2: Cooling chamber, 5: Screw portion, 7: Cooling water communication path.

Claims (1)

[Scope of utility model registration request] Place the chip body at the tip of the injection cylinder rod,
The rod is composed of a main body that communicates with and connects to the cooling water flow passage in the rod, and a sliding outer cylinder that is rotatably fitted and attached to the outside of the main body. A cooling water communication path formed in a rod shape, having a threaded portion for rod connection formed at one end thereof, and communicating with the cooling water flow path from the end face of the threaded portion to the axis directed toward the vicinity of the other end of the main body portion. A cooling chamber is formed through the sleeve, and the sliding contact outer cylinder is formed into a hollow cylindrical shape whose inner diameter is approximately the same as the outer diameter of the injection sleeve, and whose inner diameter is approximately the same as the outer diameter of the main body. A plunger tip for a die-casting machine that is rotatably inserted into the outside of the main body.