JPH0699263A - Injection plunger device of die casting machine - Google Patents

Abstract

PURPOSE:To extend durable life of a tip by eliminating irregular wear of a plunger tip. CONSTITUTION:A disk 8 is coaxially fixed on a plunger rod 3, on the outer peripheral edge part of the disk 8, plural grids 81 are radially protruded at regular interval, a guide plate 9 is arranged in parallel with the plunger rod, on the guide plate 9, a guide lane 91, which fits in one of the grids 81, is recessed in parallel with the plunger rod 3, further on the guide lane 91, a branch lane, which is branched moderately toward a low speed zone R1 from a high speed zone R2, is arranged. At the branching point, a point 93, which switches a guide lane route, is arranged, when the grid 81 travels forward from the low speed zone R1 to high speed zone R2, the point is switched such that the grid travels straight, when the grid travels backward from the high speed zone R2 to low speed zone R1, the point is switched such that the grid 81 is guided to the branch lane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection plunger device of a die casting machine for casting various products using molten aluminum or the like as a raw material.

[0002]

2. Description of the Related Art Supplying molten aluminum to a mold,
Die casting machines are commonly used to cast products of a given shape. Generally, an injection plunger device of a die casting machine is basically composed of a plunger sleeve for loading molten aluminum and a plunger rod for injecting the molten aluminum in the plunger sleeve into a mold.

A plunger tip is provided at the tip of the plunger rod, and the tip slides in the sleeve while the outer peripheral surface of the tip is in contact with the inner peripheral surface of the plunger sleeve without any gap. The molten aluminum is extruded toward the mold. The rod is moved back and forth by operating a shot cylinder provided at the base end of the rod.

Details of such a die cast machine are disclosed in, for example, Japanese Patent Laid-Open No. 3-128160.

[0005]

By the way, the die-cast machine disclosed in Japanese Patent Laid-Open No. 3-128160 is a so-called vertical type in which the plunger sleeve is arranged so as to extend in the vertical direction. There are many so-called horizontal type in which the plunger sleeve and other main devices are arranged so as to extend in the horizontal direction. In a horizontal type die-casting machine, when the plunger tip slides in the plunger sleeve, the tip is subjected to the action of gravity, so the lower part of the outer peripheral surface of the chip and the lower part of the inner peripheral surface of the sleeve slide. The resistance increases, and as a result, the uneven wear phenomenon occurs due to so-called uneven wear, in which the lower inner peripheral surface is more worn than the other parts of the plunger tip.

In recent years, the die-casting machine tends to increase in size in order to cope with the increase in size of aluminum parts. However, as the die-casting machine increases in size, the plunger rod and the tip also increase in size. As the weight of the plunger tip increases, the phenomenon of uneven wear of the plunger tip also tends to increase.

When the plunger chip is worn out, it cannot be used even if the other parts are normal, so it must be discarded, and the service life of the plunger chip increases with the increase in size of the die-cast machine. However, there is an inconvenience that

The present invention has been made to solve the above problems, and it is possible to eliminate the uneven wear of the plunger tip and thus extend the service life of the die. It is an object to provide an injection plunger device.

[0009]

In the injection plunger device of the die casting machine according to claim 1 of the present invention, the plunger sleeve in which the molten casting raw material is loaded is horizontally placed, and inside the plunger sleeve, at the tip. In the injection plunger device of the die-casting machine, which has a plunger tip and is configured to inject the raw material into the mold, and which is configured to advance and retreat, the plunger rod is advanced and retracted. It is characterized in that a plunger rod rotating means for rotating the shaft in a fixed direction by a predetermined angle is provided.

According to a second aspect of the present invention, there is provided an injection plunger device for a die casting machine according to the first aspect, wherein the driving means for the plunger rod is constant within a moving stroke of the plunger rod. It is set to drive the plunger rod at a low speed in the range and at a high speed otherwise, and the plunger rod rotating means is configured to rotate the plunger rod when the plunger rod is within the range driven at the low speed. It is characterized by that.

An injection plunger device for a die casting machine according to a third aspect of the present invention is the injection plunger device for a die casting machine according to the second aspect, wherein the plunger rod is rotated when the plunger rod is retracted. It is characterized in that a rod rotating means is configured.

According to a fourth aspect of the present invention, there is provided an injection plunger device for a die cast machine according to the third aspect, wherein the plunger rod is fixedly provided with a disk having a common axis. A plurality of grids are provided on the outer peripheral edge of the disk so as to project in the radial direction at equal intervals, and a guide plate is provided in parallel with the plunger rod. A guide to which one of the grids fits is provided on the guide plate. The lane is recessed parallel to the plunger rod, and this guide lane is provided with a branch lane that gently branches backward in the range that is driven at a low speed.At the branch point to this branch lane, the grid goes straight when moving forward. The plunger rod rotating means is configured by providing a switching point so as to guide the vehicle to the branch lane when moving backward. It is characterized in that there.

[0013]

According to the injection plunger device of the die-casting machine of the first aspect, the plunger rod rotates in a fixed direction by a preset predetermined angle by one advance / retreat of the plunger rod. The sliding surface of the lower plunger tip that receives the force with respect to the plunger sleeve changes to a new one each time the plunger rod reciprocates. Therefore, unlike the conventional case, only a fixed part of the outer peripheral surface of the plunger tip does not slide strongly against the lower part of the inner peripheral surface of the plunger sleeve to be worn away, so that the plunger chip always wears uniformly.

According to the injection plunger device of the die-casting machine of the second aspect, the low speed region and the high speed region are set for the forward / backward movement of the plunger rod, and the plunger rod is set in the low speed region at the beginning of the forward movement and the end of the backward movement. Since the plunger rod is set to advance and retreat and is configured to rotate when the plunger rod is advancing and retracting in the low speed range, it is possible to reliably and reliably rotate the plunger rod.

According to the injection plunger device of the die-casting machine of the third aspect, since the plunger rod is configured to rotate only when the plunger rod is retracting in the low speed range, the plunger rod that has once advanced is retracted. Then, when the vehicle reaches the low speed range, it is surely rotated at a predetermined angle at a low speed following the backward movement.

According to the injection plunger device of the die-casting machine of the above-mentioned claim 4, when the plunger rod is in the fixed position before it is advanced, one of the disc grids provided integrally with it is the point of the guide lane. It fits in the rear part more than. Then, when the plunger rod starts to move forward by the operation of the shot cylinder, the point in front is switched so that the grid goes straight, so the grid is guided straight by the guide lane and is provided at the tip of the plunger rod. The plunger tip injects the molten aluminum in the plunger sleeve into the mold without rotating.

After the completion of the injection, when the plunger rod is retracted by the operation of the shot cylinder, at this time, the points provided in the guide lane are switched so as to guide the grid to the branch lane.
At this point, the grid diverts diagonally to the branch lane. By changing the course of the grid, the disk rotates around the axis in the direction in which the grid is guided by a predetermined angle, so that the plunger rod integrated with the disk also rotates.

When the plunger rod is pulled back to the initial position, the grid guided to the branch lane is disengaged from the groove of the branch lane by the rotation around the axis, and the next grid is newly positioned in the guide lane. It is in a state.

Therefore, when the plunger rod moves back and forth again, the action of the grid newly fitted in the guide lane causes the plunger rod to rotate further by a predetermined angle, and this rotation in one direction repeats the forward and backward movement of the plunger rod. Will be progressed sequentially.

[0020]

1 is a side sectional view showing an example of a plunger device according to the present invention. As shown in this figure, the plunger device 1 includes a plunger sleeve 2 that is horizontally placed and is filled with molten aluminum as a casting raw material.
A plunger rod 3 provided with a plunger tip 31 at the tip for injecting molten aluminum in the plunger sleeve 2, and a shot cylinder (plunger rod driving means) 4 for moving the plunger rod 3 forward and backward.
And a guide plate 5 for guiding the rod 3 to rotate according to the advance / retreat of the plunger rod 3.

A horizontally long plunger chamber 21 is provided inside the plunger sleeve 2, and a loading hole 22 for loading molten aluminum is formed in a ceiling portion of the plunger chamber 21. Further, at the tip of the plunger sleeve 2, a mold 6 including an upper mold 61 and a lower mold 62 is formed.
The molten aluminum loaded in the plunger chamber 21 is injected into the mold 6 by the forward movement of the plunger rod 3.

The plunger rod 3 has a pipe-shaped body having a hollow inside at an intermediate portion thereof, and a cooling water passage 3a is formed by appropriately dividing the hollow portion. A plunger tip 31 is provided at the tip of the plunger rod 3, and the cooling water passage 3a is also formed inside the tip 31. A connecting portion 32 for the shot cylinder 4 having a diameter larger than that of the rod 3 is formed at the proximal end portion of the plunger rod 3. A brim-shaped portion 33 is provided at the most proximal end portion of the connecting portion 32.

On the other hand, a coupling 42 is fixed to the tip of the cylinder rod 41 of the shot cylinder 4.
A collar portion 43 is formed by folding the outer peripheral edge portion at the tip of the coupling 42 in the axial direction. Then, the collar-shaped portion 33 provided on the connecting portion 32 of the plunger rod 3 is fitted into the coupling 42, and the collar-shaped portion 33 is prevented from coming out of the coupling 42 by the collar portion 43 of the coupling 42. Has been done.

A needle bearing 44 is disposed between the inner peripheral surface of the collar portion 43 and the outer peripheral surface of the connecting portion 32, and the action of the bearing 44 allows the plunger rod 3 to be easily moved around its axis. It can be rotated to.

The tip side of the connecting portion 32 is fitted in the holder 7 having the function of a bearing. The holder 7 is provided with a cooling water supply hole 71 and a cooling water discharge hole 72. These holes 71, 72 are provided in the cooling water passage 3 a provided inside the plunger rod 3 on the inner peripheral surface of the holder 7. They communicate with each other through a groove formed in a ring shape. In order to prevent leakage of cooling water, a packing material (not shown) such as a snap ring is appropriately mounted between the inner peripheral surface of the holder 7 and the outer peripheral surface of the connecting portion 32.

A disk 8 concentric with the plunger rod 3 is fixed to the center of the connecting portion 32, and a large number of radially projecting grids 81 are formed on the outer peripheral edge of the disk 8. Has been done.

On the other hand, a guide plate 9 is provided in parallel with the plunger rod 3. A guide lane 91 into which one of the grids 81 fits is formed in the guide plate 9 in parallel with the plunger rod 3. In the guide lane 91, as shown in FIG.
A low speed region R1 on the front side and a high speed region R2 on the tip side of the central portion are set in advance. The operating speed of the shot cylinder 4 moves at a low speed when the shot cylinder 4 is in the low speed range R1, and at a high speed when the cylinder 4 is in the high speed range R2, both in forward and backward movements. Is set in advance.

FIG. 2 is a view taken along the line AA in FIG. 1. As shown in FIG. 2, the guide lane 91 has a branch lane 9 that gently branches from the high speed region R2 toward the low speed region R1.
Two are provided. A point 93 for switching the course of the guide lane 91 is provided at the branch point to the branch lane 92, and the point 93 is provided when the grid 81 advances from the low speed range R1 to the high speed range R2.
Is switched so as to go straight, and when the grid 81 moves backward from the high speed range R1 to the low speed range R2, the grid 81
Is configured to be guided to the branch lane 92.

The disc 8 and the guide plate 9 constitute a plunger rod rotating means for rotating the plunger rod 3 in a fixed direction along a path thereof by a predetermined angle.

Specifically, the right end portion of a point 93 shown in FIGS. 2 and 3 is rotatably supported by a vertical shaft 92a, and if the point 93 is rotated clockwise around the vertical shaft 92a, it is guided. A straight passage formed only by the lane 91 is formed, and when it turns counterclockwise, the guide lane 91 and the branch lane 92 communicate with each other from the high speed region R2 toward the low speed region R1.

A coil spring 92b is attached to the vertical shaft 92a, and the point 93 is constantly biased counterclockwise around the vertical shaft 92a by the biasing force of the coil spring 92b.

The operation of the present invention will be described below with reference to FIGS. FIG. 3 is a sectional view taken along line BB of FIG. 2A shows a state in which the plunger rod 3 has been pulled back from the plunger sleeve 2 to the rightmost end in FIG. 2 by the shot cylinder 4, and FIG. The state is shown in which the left end is projected and then pulled back to the root portion of the shot cylinder 4 again.

First, as shown in (a) above, one black grid X of the grid 81 is fitted to the guide lane 91. In this state, the shot cylinder 4
When the rod 41 of the grid protrudes, the grid X moves forward while being guided by the guide lane 91 and contacts the point 93, as shown in FIG.
Since the gap formed with the side of is tapered,
As the grid X advances, the point 93 is the coil spring 9
While counteracting the urging force of 2b, it rotates clockwise around a vertical axis 92a to spread the above-mentioned gap to go straight and reach the guide lane 91 in the high speed range R2, and move to the left end thereof.

When the shot cylinder 4 is actuated and the plunger rod 3 is pulled back, the guide lane 91 from the high speed range R2 to the low speed range R1 is connected to the branch lane 92 by the point 93 at the entrance of the low speed range R1. Therefore, the grid X is guided by it and moves on the branch lane 92, and according to this movement, (B) in FIG.
As shown in, the disk 8 rotates counterclockwise around the axis of the rod 3.

The grid Y adjacent to the left of the grid X is located in the guide lane 91 this time, and the grid 81 is sequentially rotated by the reciprocating motion of the plunger rod 3, so that the grid 81 is provided at the tip of the plunger rod 3. The outer peripheral surface of the plunger tip 31 and the inner peripheral surface of the bottom portion of the plunger sleeve 2 are evenly slid, and as a result, die reduction due to uneven wear of the plunger tip 31 is prevented, and the service life thereof can be extended. It will be possible.

[0036]

As described above, the injection plunger device of the die-casting machine of the present invention is configured such that the plunger rod rotates in a fixed direction by a preset predetermined angle when the plunger rod advances and retracts once. Therefore, the sliding surface of the lower plunger tip that receives the greatest force due to gravity against the plunger sleeve is
It changes with each reciprocating movement of the plunger rod.
Therefore, unlike the prior art, only a fixed part of the outer peripheral surface of the plunger tip does not slide strongly against the lower part of the inner peripheral surface of the plunger sleeve and is not worn away. It is possible to significantly extend the service life of.

With respect to the forward / backward movement of the plunger rod, the low speed region and the high speed region are set, and the plunger rod is set to move forward / backward in the low speed region at the initial stage of forward movement and the final stage of backward movement.
If the plunger rod is configured to rotate while advancing and retracting in the low speed range, it is convenient because the plunger rod can be rotated without fail without fail.

In particular, if the plunger rod is configured to rotate only when it is retracting in the low speed range, the plunger rod is rotated when it is retracted with no load, so that the plunger rod rotates reasonably and satisfactorily.

A disk having a common axis is fixedly mounted on the plunger rod, and a plurality of grids are projected at equal intervals on the outer peripheral edge of the disk. A guide plate is provided parallel to the plunger rod. A guide lane to which one of the grids fits is provided in the plate in parallel with the plunger rod, and a branch lane that gently branches from the high speed region to the low speed region is provided on this guide lane. A point for switching the course of the guide lane is provided at the branch point, and this point is switched so that the grid goes straight when the grid moves forward from the low speed range to the high speed range, and the grid retreats from the high speed range to the low speed range. When the grid is configured to switch to guide the lane to the branch lane, the Fitted in the rear portion than one guide lane point of a disk provided integrally grid.

Then, when the plunger rod starts to move forward by the operation of the shot cylinder, the point in front is switched so that the grid goes straight, so the grid is guided by the guide lane and goes straight, and the tip of the plunger rod moves. The molten aluminum in the plunger sleeve is injected into the mold without rotating the plunger tip provided in the mold.

After the injection is completed, when the plunger rod is retracted by the operation of the shot cylinder, the points provided in the guide lane at this time are switched so as to guide the grid to the branch lane.
At this point, the grid diverts diagonally to the branch lane. By changing the course of the grid, the disk rotates around the axis in the direction in which the grid is guided by a predetermined angle, so that the plunger rod integrated with the disk also rotates.

When the plunger rod is pulled back to the initial position, the grid guided to the branch lane is disengaged from the groove of the branch lane by the rotation around the axis, and the next grid is newly positioned in the guide lane. It is in a state.

Therefore, when the plunger rod moves back and forth again, the action of the grid newly fitted in the guide lane causes the plunger rod to further rotate by a predetermined angle, and this rotation in one direction repeats the forward and backward movement of the plunger rod. Will be progressed sequentially.

As described above, since the plunger rod sequentially rotates, the sliding portion of the outer bottom surface of the plunger tip attached to the tip portion of the plunger rod with respect to the inner bottom surface of the plunger sleeve is sequentially and evenly changed, and only a part of the tip is replaced. Damage due to wear is avoided, which can contribute to the extended life of the plunger tip.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an injection plunger device of a die casting machine according to the present invention.

FIG. 2 is an AA diagram of FIG.

3A and 3B are explanatory views for explaining a rotating state of a disk fixedly mounted on a plunger rod, in which (A) is a state where the grid X is fitted in the guide lane, and (B) is a grid X.
Shows that the disk is guided to the branch lane when it retreats and the disk rotates counterclockwise by a predetermined angle.

[Explanation of symbols]

 1 Plunger device 2 Sleeve 21 Plunger chamber 22 Loading hole 3 Plunger rod 31 Plunger tip 32 Connecting part 33 Collar part 4 Shot cylinder 41 Cylinder rod 42 Coupling 43 Collar part 44 Needle bearing 5 Guide plate 6 Mold 61 Upper mold 62 Lower Type 7 Holder 71 Cooling water supply hole 72 Cooling water discharge hole 8 Disc 81 Grid 9 Guide plate 91 Guide lane 92 Branch lane 93 Point R1 Low speed range R2 High speed range

Claims (4)

[Claims] 1. A plunger sleeve in which a molten casting raw material is loaded is horizontally placed, and a plunger rod having a plunger tip at its tip for injecting the raw material into a mold is fitted into the plunger sleeve. In the injection plunger device of the die-casting machine configured such that the plunger rod advances and retracts, plunger rod rotating means for rotating the plunger rod in a fixed direction by a predetermined angle as the plunger rod advances and retracts is provided. An injection plunger device for a die-casting machine. 2. The plunger rod driving means is set so as to drive the plunger rod at a low speed within a certain range within the movement stroke of the plunger rod, and otherwise at a high speed, and the plunger rod is driven at the low speed. 2. The injection plunger device for a die casting machine according to claim 1, wherein the plunger rod rotating means is configured to rotate the plunger rod when it is within the range. 3. The injection plunger device for a die casting machine according to claim 2, wherein the plunger rod rotating means is configured to rotate the plunger rod when it is retracted. 4. A disk having a common axis is fixedly provided on the plunger rod, and a plurality of grids are provided on the outer peripheral edge of the disk at equal intervals in a radial direction so as to project in parallel with the plunger rod. A guide plate is provided on the guide plate, and a guide lane into which one of the grids fits is provided in the guide plate in parallel with the plunger rod, and the guide lane is gently branched rearward in a range driven at a low speed. A branch lane is provided, and at the branch point to this branch lane, a point is provided to switch the grid so that the grid goes straight when moving forward and guides to the branch lane when moving backward. The injection plunger device of the die-casting machine according to claim 3, wherein