JP2597248Y2 - Injection plunger - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an injection plunger of a cold chamber type die casting machine, and more particularly to improvement of wear resistance of a plunger tip and workability at the time of replacement.

[0002]

2. Description of the Related Art A typical structure of a conventional injection plunger will be described with reference to FIG. In the figure, a plunger tip 32 is slidably inserted into the injection sleeve 10 and screwed together with a joint 31 between the plunger rod 33 to form an injection plunger 34. A piston rod of an injection cylinder (not shown) is connected to the right end of the plunger rod 33 via a coupling. The plunger tip 32 has a cooling hole 35 formed in the inside thereof, and a discharge fluid passage 39 which communicates with the hole 35 of the plunger tip 32 and penetrates the joint 31 and the plunger rod 33 is formed in the plunger rod 33. Connected to the discharge port 36, the small-diameter cooling fluid supply pipe 4
1 and connected to a cooling fluid supply port 37 also provided on the plunger rod 33 to supply cooling fluid (not shown).
The cooling fluid is supplied and discharged from the discharge device.

[0003]

However, in order to screw and connect the plunger tip 32 and the plunger rod 33 with the joint 31 as described above, the central part of the joint 31 is made hexagonal and a large spanner is used. Using a tightening tool such as 2
This is a labor-intensive task, such as when replacing the injection sleeve by replacing the mold or performing maintenance due to wear over time.
The workability when removing and attaching the plunger tip was poor. In addition, twisting and one-sided contact between the inner surface of the injection sleeve and the outer periphery of the plunger chip occur due to concentricity errors that occur in the processing accuracy and assembly accuracy of individual parts and thermal deformation that is affected by high-temperature molten metal. However, this causes galling and abnormal wear, causing problems during operation and shortening the service life of the injection sleeve and the plunger tip.

Further, when the plunger tip is cooled with a cooling fluid, the cooling hole 35 inside the plunger tip 32 is partially in a liquid reservoir state and tends to be biased. The efficiency and circulation efficiency of the cooling fluid are reduced.

In view of the above, the present invention has been made in view of the above points, and does not cause twisting or one-sided contact due to misalignment between the injection sleeve and the plunger tip and the plunger rod. It is an object of the present invention to provide an injection plunger that improves workability when attaching and detaching the plunger to and from a rod and further increases the cooling efficiency of a plunger tip.

[0006]

An injection plunger according to the present invention, which has been made to achieve the above object, has a plunger tip having a cup-shaped hole and a tip inserted into the cup-shaped hole of the plunger tip. A plunger rod pressed against the bottom surface of the cup-shaped hole, a connecting member detachably mounted in a groove formed in an inner wall of the cup-shaped hole of the plunger tip and an outer periphery of the plunger rod, and integrally connecting the two; A cooling fluid passage formed between the cup-shaped hole of the plunger rod and a tip of the plunger rod; a supply / drainage fluid passage provided inside the plunger rod so as to communicate with the cooling fluid passage; and a cup-shaped hole opening end of the plunger tip. In an injection plunger provided with a sealing gasket mounted in the vicinity between the outer periphery of the plunger rod in a liquid-tight manner,
The tip of the plunger rod pressed against the bottom surface of the cup-shaped hole of the plunger tip is formed into a slightly spherical surface, and a small gap is formed between the inner wall of the cup-shaped hole of the plunger tip and the outer periphery of the plunger rod. A cooling fluid passage which also provides self-alignment between the plunger tip and the plunger rod; and a self-alignment between the plunger tip and the plunger rod formed by forming the groove into a V-shaped groove and connecting cylindrical rollers. The connecting member having a degree of freedom in the center direction and the supply / drainage fluid passage inside the plunger rod are enlarged.
.Formed of a small-diameter double pipe and having the cooling fluid passage formed of a plurality of lateral holes
And a plurality of jet ports provided at the end of the plunger rod and communicating with the distal end of the water supply fluid passage of the small diameter pipe .

[0007]

[Action] A plunger rod tip is inserted into the cup-shaped hole of the plunger tip with a slight gap provided on the outer periphery thereof, and the plunger rod and the plunger tip are automatically engaged by engaging a detachably mounted connecting member in the groove. The injection plunger provided with the aligning property smoothly slides the injection sleeve back and forth without causing twisting or one-sided contact, and the occurrence of galling and wear is significantly reduced. In addition, replacement of the plunger tip can be easily performed by attaching and detaching the connecting member from the groove. Further, by jetting the cooling fluid to the bottom surface of the cup-shaped hole of the plunger tip, the plunger tip can be cooled with good heat conduction efficiency.

[0008]

1 shows an embodiment of an injection plunger according to the present invention.
It will be described in detail based on. The figure shows, in an enlarged manner, a characteristic part of the structure of the injection plunger according to the present invention. In the drawing, reference numeral 10 denotes a part of an injection sleeve of a horizontal cold chamber type die casting machine. Numeral 12 denotes a plunger tip, and numeral 13 denotes a plunger rod, which are combined as described later to form an injection plunger 14. The plunger tip 12 is slidably inserted into the injection sleeve 10, and the right end of the plunger rod 13 is connected to a piston rod of an injection cylinder (not shown) via a coupling.

The plunger tip 12 has a cup-shaped hole 1.
5 is formed, a groove is provided on the inner side near the open end of the hole 15, and a sealing gasket 16 is attached.
3 is inserted into the cup-shaped hole 15 of the plunger tip 12 in a liquid-tight manner by the packing 16, and the tip thereof is pressed against the bottom face 17 of the cup-shaped hole, and the outer periphery of the inserted plunger rod 13 and the inner wall of the cup-shaped hole 15. A slight gap is formed between the two and also serves as a cooling fluid passage 18. Further, the tip of the plunger rod 13 pressed against the bottom face 17 of the cup-shaped hole of the plunger tip 12 forms a slight spherical surface (a spherical surface having a large radius), and both the pressing surfaces have high hardness by quenching. To improve the abrasion resistance of the plunger rod 13 and the cup-shaped hole 1.
5 and a small gap (cooling fluid passage 1)
In the range of 8), self-alignment is provided between the plunger rod 13 and the plunger tip 12.

Reference numeral 19 denotes a drainage fluid passage which is bored inside the plunger rod 13 and has a left end communicating with the cooling fluid passage 18 through a plurality of lateral holes 20 provided inside the position of the packing 16. Is connected to a discharge port (36) provided in the plunger rod 13 as in the prior art (see FIG. 2). Reference numeral 21 denotes a cooling fluid supply pipe, and a pipe having a diameter smaller than that of the drainage fluid passage 19 is penetrated substantially concentrically,
The left end thereof communicates with a plurality of ejection ports 22 provided at the end of the plunger rod 13, and the right end (not shown) has a cooling fluid supply port (3) provided in the plunger rod 13 as in the prior art.
7) (see FIG. 2). On the end face of the plunger rod 13 pressed against the bottom face 17 of the cup-shaped hole of the plunger tip 12, a plurality of grooves 23 are formed, for example, radially, and the jet port 22 is opened for each groove 23.

Reference numeral 24 denotes a cylindrical roller, which is a plunger rod 1 connected to an injection cylinder (not shown) via a coupling.
3 is a connecting member for retreating the plunger tip 12 to the right in the figure, a V-shaped groove 25 provided on the outer periphery of the plunger rod 13 and a cup-shaped hole of the plunger tip 12 at a position outside the packing 16. 15 V provided on the inner wall
A large number are inserted and inserted between the groove 26 and engaged.
In this case, the cylindrical roller 24 and the V-shaped groove 25 have a degree of freedom that does not impair the self-alignment provided between the plunger rod 13 and the plunger tip 12.
26 are engaged. At least one screw hole 27 is threaded from the outer periphery of the plunger tip 12 toward the V-shaped groove 26, so that the cylindrical roller 24 can be inserted and removed from the outside of the plunger tip 12. The screw hole 27 is closed by screwing a removable plug 28. In addition, the connecting member and the groove engaged with the connecting member are not limited to the cylindrical roller and the V-shaped groove. For example, the cylindrical roller may be a steel ball, and the V-shaped groove may be an annular groove. The good is clear.

Injection plunger 1 configured as described above
4, the plunger rod 13 is connected via a coupling by the operation of a piston rod of an injection cylinder (not shown).
Moves forward in the left direction in the figure, the plunger rod 13
When the plunger tip 12 moves forward in the injection sleeve 10 by pressing the cup-shaped hole bottom face 17 of the plunger tip 12 at the tip and the plunger rod 13 retreats rightward in the drawing, the outer periphery of the plunger rod 13 and the plunger tip 12 V-shaped groove 2 provided opposite to the inner wall of the cup-shaped hole 15 of FIG.
The engagement of the cylindrical roller 24, which is a connecting member, with the injection sleeve 10 and the injection sleeve 10.
Retreat inside. In this case, self-alignment is provided between the plunger rod 13 and the plunger tip 12, and the plunger tip 12 can slide smoothly within the injection sleeve 10 without difficulty. Of the plunger tip 12 and the inner surface of the injection sleeve 10 due to the concentricity error and the thermal deformation caused by the high-temperature molten metal are eliminated, and the occurrence of galling and wear is significantly reduced.

When replacing the plunger tip 12, the unillustrated coupling of the plunger rod 13 is removed, the plunger tip 12 is pulled out of the injection sleeve 10, and the plug 28 screwed into the screw hole 27 of the plunger tip 12 is loosened. Remove and take out a number of cylindrical rollers 24 continuously connected to the V-shaped grooves 25 and 26 from the screw holes 27 in order,
By releasing the connection between the plunger rod 13 and the plunger tip 12, the plunger tip 12 can be removed from the plunger rod 13. After the new plunger tip 12 is inserted into the plunger rod 13, the V-shaped grooves 25, 26 are inserted through the screw holes 27 in the reverse order.
A number of cylindrical rollers 24 are inserted one after another, and a large number of them are successively connected. The plug 28 is screwed into the screw hole 27 again, and the operation is completed. In this case, two or three screw holes 27 are provided.
By providing them at two places, the work of inserting and removing the cylindrical roller 24 can be performed more quickly.

Next, the flow of the cooling fluid for cooling the outer periphery of the plunger tip 12 in contact with the high-temperature molten metal flows in from a cooling fluid supply port (see reference numeral 37 in FIG. 2) at the right end of the plunger rod 13 (not shown). The cooling fluid supply pipe 21 flows leftward in the figure, and a plurality of jet ports 22 opening in a plurality of grooves 23 radially formed in the end face of the plunger rod 13 to form a cup-shaped hole bottom face 17 of the plunger tip 12.
After jetting at a high flow rate toward the plunger tip 12 to perform a cooling action with high heat conduction efficiency on the plunger tip 12, the plunger flows from the groove 23 through the cooling fluid passage 18 in the gap between the outer periphery of the plunger rod 13 and the inner wall of the cup-shaped hole 15. The rod 13 returns from the plurality of lateral holes 20 to the drainage fluid passage 19 in the plunger rod 13, flows rightward in the drawing, and is discharged from a discharge port (not shown in FIG. 2).

[0015]

According to the injection plunger according to the present invention,
Insert the tip of the plunger rod into the cup-shaped hole of the plunger tip with a slight gap around its outer periphery,
The spherical surface of the cup-shaped hole is quenched with high hardness to improve the abrasion resistance, and the spherical surface of the tip is pressed to provide self-centering between the plunger rod and the plunger tip.
When the plunger tip slides back and forth on the inner surface of the injection sleeve, the concentricity error in processing accuracy and the deformation of the inner surface of the injection sleeve and the outer periphery of the plunger tip and the inner surface of the injection sleeve due to thermal deformation due to high-temperature molten metal are eliminated, causing galling and wear. Is significantly reduced, and the wear resistance of the injection sleeve and the plunger tip can be improved. Further, since the plunger tip is cup-shaped and short, the weight is reduced, handling operability at the time of replacement is improved, and deep hole processing of the cup-shaped hole is facilitated. The plunger rod and the plunger tip have a plurality of cylindrical rollers connected to the V-shaped groove as a connecting member, and the cylindrical roller is easily inserted and removed from a screw hole with a plug that communicates with the V-shaped groove. Since the connection of the plunger tip is detached, the replacement of the plunger tip can be performed very easily in a short time without requiring excessive labor.

Further, in order to cool the outer periphery of the plunger tip which is in contact with the high-temperature molten metal, a cooling fluid is supplied from a spout opening to a plurality of radial grooves formed in the tip end surface of the plunger rod which is pressed against the bottom of the cup-shaped hole of the plunger tip. By injecting water at a high flow rate, a cooling action with high heat conduction efficiency can be performed on the plunger tip, and at the same time, there is an effect of saving water.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view of the structure of an injection cylinder according to the present invention .
FIG.

FIG. 2 is a sectional view showing the structure of a conventional injection cylinder.
You.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Injection sleeve 12 Plunger tip 13 Plunger rod 14 Injection plunger 15 Cup-shaped hole 16 Packing 17 Cup-shaped hole bottom surface 18 Cooling fluid passage 19 Drainage fluid passage 20 Side hole 21 Cooling fluid supply pipe 22 Spout outlet 23 Groove 24 Cylindrical roller 25 V-shaped groove 26 V-shaped groove 27 Screw hole 28 Plug

Claims (1)

(57) [Scope of request for utility model registration] 1. A plunger tip having a cup-shaped hole formed therein, a plunger rod inserted into the cup-shaped hole of the plunger tip and having a tip pressed against the bottom surface of the cup-shaped hole, an inner wall of the cup-shaped hole of the plunger tip and the plunger rod. A connecting member detachably mounted in a groove provided on the outer periphery and integrally connecting the two, a cooling fluid passage formed between a cup-shaped hole of the plunger tip and a tip of the plunger rod; Injection having a supply / drainage fluid passage provided inside the plunger rod so as to communicate with the passage, and a sealing gasket mounted in a liquid-tight manner between the plunger tip and the outer periphery of the plunger rod near the opening end of the cup-shaped hole. In the plunger, the tip of the plunger rod pressed against the bottom surface of the cup-shaped hole of the plunger tip is formed into a slightly spherical surface, and A cooling fluid passage which also serves to provide a self-alignment between the plunger tip and the plunger rod by forming a slight gap between the inner wall of the cup-shaped hole of the plunger tip and the outer periphery of the plunger rod; Is formed in a V-shaped groove, a cylindrical roller is continuously provided, and a connecting member having a degree of freedom in the self-aligning direction between the plunger tip and the plunger rod ;
Supply / drain fluid passages are formed by large / small diameter double pipes for cooling
Connect the fluid passage to the large-diameter drainage fluid passage with multiple lateral holes
And a plurality of ejection ports provided at the end of the plunger rod and communicating with the tip of the water supply fluid passage of the small diameter pipe .