JPH059141Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can be used when forming a bent pipe that has a bent part such as an elbow or bend and has a straight part at one end of the pipe. The present invention relates to a suitable injection mold, and particularly to an improvement for releasing a molded bent tube.

[Conventional technology]

Conventionally, an injection mold suitable for use when molding a bent pipe having a bent part such as an elbow or a bend and including a straight part at one end of the pipe is, for example, Japanese Patent Publication No. 61-4335. As described in the above publication, there is known a device equipped with a rotating ironing bar for releasing a molded bent tube from a mold.

[Problem that the invention attempts to solve]

However, conventional molds that are equipped with a rotating ironing bar to release the bent tube from the mold follow the rotation of the rotating ironing bar as the angle changes when the bent tube is released from the mold. However, as shown in FIG. 7, the stroke S of the rotary squeezing bar 30 is limited because it is caused by the rotation of the rotary squeezing bar 30, and the size of the bent tube 1 becomes smaller. When the thickness t of the end portion becomes smaller, the end portion of the bent tube 1 rotates as the ironing bar 30
There is a drawback that the rotating ironing bar 30 does not get caught and the rotating ironing bar 30 misses, resulting in poor mold release.

"Means for Solving the Problems" The present invention was made to solve the above-mentioned drawbacks of the conventional injection molds, and it is possible to reliably mold even if the thickness of the end of the bent pipe becomes small. A movable mold and a fixed mold that form a female mold having a bent part and a shape that matches the outer shape of a bent pipe including a straight part at one end of the pipe; In an injection mold that has a plurality of cores that are inserted into the female mold to form mold cavities, and a stripper that removes the molded bent tube from the movable mold, an outer shell attached to the stripper is used. A cam rod protruding from a movable mold is inserted into the hole of the ironing rod in the box, and the tip of the ironing rod is moved back and forth between the end face of the bent tube formed by the movement of the movable mold and the core. An injection mold is characterized in that the mold is configured as follows.

[Effect]

In the present invention, a cam rod protruding from a movable mold is inserted into a hole in an ironing rod in an outer box attached to a stripper, and the tip of the ironing rod is inserted into a bent pipe formed by the movement of the movable mold. The tip of the ironing rod enters between the end face and the core and is retracted, so when the movable mold opens after forming the bent pipe, the tip of the ironing rod enters between the end face of the bent pipe and the core, and the ironing rod Since the stroke of the cam can be determined by the shape of the cam, it is possible to reliably release the mold even if the thickness of the end of the bent tube becomes small.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a bent pipe having a straight pipe portion 1a at one end such as an elbow, 2 is a fixed mold,
3 is a side-opening movable mold. A female mold 4 is formed in the stationary mold 2 and the movable mold 3, which conforms to the outer shape of a bent pipe having straight pipe parts at both ends and a bent pipe part in the center when both molds are closed.

5 to 7 are cores inserted into the female mold 4 to form a mold cavity, 5 is a first core for molding the curved pipe portion, and 6 is a second core for molding the straight pipe portion. 7 is a third core for forming the other end of the bent tube 1. The end of the third core 7 in the mold cavity is brought into close contact with the end of the first core 5 during molding, and the vertical movement is controlled by the hole extending from the fixed mold 2.
This is done by the action of an angular pin (not shown) that engages a.

The first core 5 has a smaller diameter at one end in the withdrawal direction, and further has a guide portion 8 of a predetermined length that continuously maintains the same diameter and extends outside the mold cavity so that the axis line coincides with the parting line PL during molding. However, a guide block 9 is provided at the end of the guide portion 8 on the side opposite to the mold cavity. This guide block 9 has a vertical width and a horizontal width that are larger than the diameter of the guide part 8, and as shown in FIG. Groove engagement is possible. In the figure, 11 is the guide block 9
12 is a guide groove.

The movable core plate 10 is attached to the parting line of the movable mold 3 on the outside of the female mold of the movable mold 3.
It is housed in a recess 13 formed to a predetermined depth from the PL, and guide holes 14 are provided at each of the four corners.
The movable mold 3 is guided in the direction of movement by a guide pin 15 passing through the movable mold 3.

16 is a presser roll whose axis is on the parting line PL, and the first core 5 when the mold is closed.
It is rotatably supported by a horizontal support frame 17 at a position where it contacts the center of the rear end surface of the guide block 9. This horizontal support frame 17 is attached to the movable mold 3 and passes through the movable core plate 10 in a loosely fitted manner. Reference numeral 18 denotes a stopper which is erected on the movable mold 3 at a predetermined distance from the presser roll 16.

Second core 6 for forming the straight pipe portion of the bent pipe 1
is a tubular core which is fitted on the outside of the small diameter portion of the first core 5, and has a guide block 19 at the end outside the mold cavity.
is provided. This guide block 19 has the same length and width as the corresponding width of the guide block 9 of the first core 5, and the small diameter portion of the first core 5 passes through it. A predetermined linear distance L is provided between the opposing end surfaces of the guide blocks 9 and 19. Further, the guide block 19 of the second core 6 is engaged in a groove in the same surface of the movable core plate 10 as the guide block 9 of the first core 5 so as to be non-separable and slidable in the direction of the mold cavity of the second core 6. There is.

20 and 21 are roll cam followers, respectively.
It is rotatably held at the center of the upper and lower surfaces of the guide block 19 of the core 6 (positions corresponding to the parting line PL).

Reference numerals 22 and 23 denote angular plates of the same shape, which are arranged opposite to each other with approximately the vertical width of the guide block 19 of the second core 6 in between. 2
5 and facing the long holes 24 and 25 formed at the bottom of the recess 14 of the movable mold 3, respectively.
6 and 27. Anguilla plate 2
2 and 23, there is an inclined cam groove 28 of a predetermined length that is inclined toward the guide block 9 of the first core 5 and forms a predetermined angle θ with respect to the parting line PL, starting from a position corresponding to the parting line PL. and a parting line that is continuous with this inclined cam groove 28.
A cam groove 29 is formed in a direction perpendicular to PL. When the mold is closed, the roll cam followers 20 and 21 attached to the guide block 19 of the second core 6
are locked at the starting positions in the inclined cam grooves 28 of the angular plates 22 and 23, respectively.

31 is a ladder bar, and a compression spring 3 is attached to the outer box attached to a stripper (not shown) so that it can be raised and lowered.
4 (see FIG. 6), a cam rod 33 whose middle part is bent is inserted into the hole 311 of the ironing rod 31, and one end of the cam rod 33 is attached to the movable mold 3. , when the movable mold 3 moves, the bent cam rod 33 connects to the hole 31 of the ironing rod 31.
1, the straining rod 31 descends and its tip enters between the end of the bent tube 1 and the core 6. The stroke of the lifting and lowering of the straining rod 31 can be increased by increasing the degree of bending of the cam rod 33.

Next, the operation of the above-mentioned injection mold of the present invention will be explained.

When mold opening is started and the movable mold 3 is pushed against the fixed mold 2 in the direction of the solid line arrow shown in FIG. 2 by a driving device such as a hydraulic cylinder (not shown), the third
The core 7 is pulled down from the fixed mold 2 in the direction of the solid line arrow shown in FIG. 1, that is, downward, by the action of an unillustrated angular pin that is engaged with the elongated diagonal hole 7a.

At the same time, roll cam followers 20 and 21
are guided by the inclined cam grooves 28 of the angular plates 22 and 23, respectively, and the guide block 19 of the second core 6 is slidably fitted onto the guide portion 8 of the first core 5. Due to the axial pressure of the acting guide portion 8, the second core 6 is moved from the guide block 19 to the guide block 9 of the first core 5.
It is pulled out as shown by the solid line arrow in FIG. 1 until it comes into pressure contact with . At this time, the roll cam followers 20 and 21 are still engaged with the inclined cam groove 28. Also, during this time, the first core 5 is in the same position as before the start of mold opening.

When the guide block 19 of the second core 6 comes into contact with the guide block 9 of the first core 5, the guide block 9 is prevented from moving in the direction of the solid line arrow in FIG. However, since the movable mold 3 continues to be separated from the fixed mold 2, the angular plates 22, 2
3 and the roll cam followers 20 and 21, the movable core plate 10 is pushed out from the movable mold 3 toward the fixed mold 2, and at the end, the presser roll 16 is pushed out as shown in FIG. It then comes off the rear end surface of the guide block 9 and reaches a level where it can engage with one side surface. At this time, the roll cam followers 20 and 21 are still engaged with the inclined cam grooves 28 of the corresponding angular plates 22 and 23, so when the mold opening continues, the guide block 19 of the second core 6 is again subjected to a force in the direction shown by the solid line arrow in FIG. 4, and the guide block 9 of the first core 5
Press in the same direction.

Since the guide block 9 is slidably engaged with the movable core plate 10 in the direction of the solid arrow, it is pushed by the guide block 19 and starts moving toward the stopper 18. When this movement starts, the bent pipe 1 also tries to move together with the first core 5, but since the straining rod 31 is in contact with the end face of the straight pipe part of the bent pipe 1, the bending pipe 1 is bent as the first core 5 moves. tube 1
rotates downward about the center of the arc of the curved surface of the first core 5 as a rotation fulcrum. During this time, the rod 31
descends and enters between the bent pipe 1 and the core 6.

As the bending tube 1 continues to rotate, due to its draft angle,
A slight gap is created between the first core 5 and the inner peripheral surface of the bent tube 1, and the bent tube 1 completely separates and falls from the first core 5 due to its own weight, as shown in FIG. On the other hand, the first
The core 5 comes into contact with the stopper 18 and stops.

In the above embodiment, a bent pipe such as an elbow was described, but the present invention can also be applied to a bent pipe such as a cheese or cloth having a bent portion.

〔effect〕

In the present invention, a cam rod protruding from a movable mold is inserted into the hole of the ironing rod in the outer box attached to the stripper, and the tip of the ironing rod is brought into contact with the end face of the bent pipe and the core by the movement of the movable mold. The stroke of the ironing rod can be increased depending on the shape of the cam rod, and even if the thickness of the end of the bent tube becomes small, it can be reliably released from the mold. be.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a movable mold seen from the fixed mold side according to an embodiment of the present invention, Fig. 2 is an arbitrary sectional view in Fig. 1, and Fig. 3 is a view taken along the - line in Fig. 2. The sectional views, FIGS. 4 to 6 are explanatory views of the operation of the above embodiment, and FIG. 7 is an explanatory view showing the prior art. 2...Fixed mold, 3...Moveable mold, 5, 6, 7
... Core, 31 ... Straining rod, 311 ... Hole, 3
2...Outer box, 33...Cam rod.

Claims (1)

[Scope of utility model registration request] A movable mold and a stationary mold that form a female mold having a bent part and a straight pipe part at one end of the pipe that matches the external shape of the bent pipe, and are inserted into this female mold to form a mold cavity. In an injection mold that has a stripper that removes the molded bent tube from the moving mold, the molded bent tube is inserted into the hole of the ironing rod in the outer box attached to the stripper. Injection molding characterized in that a protruding cam rod is inserted through the ironing rod, and the tip of the ironing rod is moved between the core and the end face of the bent tube formed by the movement of the movable mold. Mold for use.