JPH04176621A - Locking device of ejector plate of injection mold - Google Patents

Abstract

PURPOSE:To make the sure engagement and disengagement of the groove of a locking member to a locking pin possible by a structure wherein the title device is provided with a disengaging side cam block, which rocks the locking member to the direction so as to disengage the locking pin from the groove, and an engaging side cam block, which rocks the locking member to the direction so as to engage the locking pin with the groove through the backward movement of a rear side ejector plate facing to a movable mounting plate. CONSTITUTION:Both a rear side ejector plate 7 and a front side ejector plate 8 together retreat until the rear side ejector plate 7 abuts against a movable mounting plate 6, the engaged posture of a locking member 33 is held by the sliding contact between the side 37b of an engaging side cam block 37, resulting in surely coupling the rear side ejector plate 7 with the front side ejector plate 8 by means of locking device 28. Accordingly, by means of the locking device 28, the locking member 33 is rocked like a positive cam by a disengaging side cam block 35 and an engaging side cam block 37 and not by the elastic force of a spring, resulting in surely engaging and disengaging a locking pin 29 with and from the groove 31a of the locking member 33. Thus, the bonding between the front side ejector plate and the rear side ejector plate can be surely released with simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a locking device for an ejector plate of an injection molding mold, which has a simple structure and operates reliably.

(Prior art) When forming, for example, a product with an undercut using an injection mold, two ejector plates are integrally joined to a predetermined forward position when the mold is opened, and the product is The product and the insert are sometimes extruded together from the movable mold plate, and then the two ejector plates are separated and only one ejector plate is moved further forward to separate the product and the insert, and it is used in such cases. Conventionally, there is a locking device for an ejector plate, such as the one shown in cross section in FIG. 8, for example.

This lock device 1 consists of a lock plate 2 having a partially cylindrical recess 2a or a protrusion 2b formed on both sides, and a lock body 3.The lock body 3 has a lock plate 2 formed in the center thereof. It has a pair of rollers 4 that can move in and out of the hole 3a that accommodates the protrusion 2b, and a pair of springs 5 that constantly bias the rollers 4 so that they protrude into the hole 3a.

9 to 11 show the operating state of the injection molding mold equipped with the locking device 1, in which 6 indicates a movable side mounting plate;
7 is a rear ejector plate to which the lock body 3 is fixed to the side surface, 8 is a front ejector plate to which the lock plate 2 is fixed to the side surface, and 9 is a direction in which the rear ejector plate 7 is separated from the movable mounting plate 6. The stripper bolt has a shaft portion of a predetermined length thicker than the tip threaded portion, and 10 indicates an extrusion rod of the injection molding device.

In this injection mold, in the mold clamping state shown in FIG. 9(a), the protrusion 2b of the lock plate 2 is inserted into the hole 3a of the lock body 3, as shown in FIG. 9(b). is,
The concave portions 2a on both sides of the protrusion 2b engage with the pair of rollers 4 that are suppressed by the springs 5, and the rear ejector plate 7 and the front ejector plate 8 are integrated as shown in FIG. are connected to each other.

From this state, as shown in FIG. 1θ (a), as the mold opens, the extrusion rod 10 advances to the right, and its tip presses the front ejector plate 8 or the movable mold plate (not shown). When moving forward in the direction approaching the locking device l, as shown in FIG.
The rear ejector plate 7 connected to the front ejector plate 8 contacts the head of the stripper bolt 9 or the bottom of the counterbore of the movable mounting plate 6 to restrict the forward movement of the rear ejector plate 7. and moves forward together with the front ejector plate 8.

As shown in FIG. 11(a), the head of the stripper bolt 9 comes into contact with the bottom of the dust hole to restrict further forward movement of the rear ejector plate 7.
As shown in b), the protrusion 2b of the lock plate 2 pushes back the pair of rollers 4 against the spring 5 due to the pressing force of the push rod 10, and pushes the pair of rollers 4 back into the hole 3 of the lock body 3.
By being pulled out from inside a, the locking device 1 releases the front ejector plate 8 from the rear ejector plate 7, and only the front ejector plate 8 moves further forward, as shown in FIG.

On the other hand, when closing the mold from the mold open state, the front ejector plate 8, which is pushed back by a return pin (not shown) and moves backward as the extrusion rod lO retreats, pushes the protrusion 2b of the lock plate 2 onto the lock body 3. The rear ejector plate 7 is pressed by the contact between the protrusion 2b and the pair of rollers 4, and is moved backward toward the movable mounting plate 6.

When the rear ejector plate 7 comes into contact with the movable mounting plate 6, the protrusion 2b of the lock plate 2 pushes back the pair of rollers 4 against the spring 5 and completely inserts them into the hole 3a of the lock body 3. and its protrusion 2
The concave portions 2a on both sides of b engage with the rollers 4 again to integrally connect the rear ejector plate 7 and the front ejector plate 8 as shown in FIG. 9(a).

FIG. 12 is a sectional view showing another example of the conventional locking device, and the locking device 11 of this example includes a release par 12 fixed to the side surface of the fixed side mounting plate 6, and a side surface of the rear ejector plate 7. a slide holder 13 fixed to the
A cam holder 14 is fixed to the side surface of the front ejector plate 8.

Here, the slide holder 13 has - number of slide claws 1 so as to be retractable into the hole 13a through which the release par 12 is inserted.
5, and one spring 16 that constantly biases the slide claw 15 to protrude into the hole 13a.

Further, the cam holder 14 swingably supports the cam plate 17 by means of a pin in a hole 14a through which the release par 12 is inserted, and always swings the cam plate 17 in the direction in which the cam plate 17 is released from the slide pawl 14. As shown in FIG. 13, the ball plunger 18 has a cylindrical shape with a male thread formed on its outer circumferential surface, and a pole is provided inside the cylinder so as to be retractable from one end. 18a, and the pole 18
It is provided with a spring 18b that always urges outward.

In an injection mold equipped with this locking device 11,
As shown in FIG. 12(a), as the mold opens, the front ejector plate 8 is pressed by an extrusion rod (not shown) and moves forward in the direction (to the right in the figure) approaching the movable mold plate (not shown). Until the forward movement of the ejector plate 7 is regulated by a stripper bolt (not shown), the release par 12 inserted into the hole 13a of the slide holder 13 or the cam plate 17 supported by the cam holder 14 is attached to the slide claw 15. continue to connect the rear ejector plate 7 to the locking device 11 or its front ejector plate 8 by restraining it in the engaged position;
As a result, the rear ejector plate 7 moves forward together with the front ejector plate 8.

As a result, when the further forward movement of the rear ejector plate 7 is restricted, at the same time, the movement shown in FIG. 12 (
As shown in b), release par 12 or cam plate 1
7 is allowed to swing, and the ball plunger 18 or the cam plate 17 is allowed to swing in the direction of detachment from the slide claw 15, thereby releasing the front ejector plate 8 from the locking device 11 or the rear ejector plate 7, and then As shown in FIG. 3(b), only the front ejector plate 8 moves further forward.

On the other hand, when closing the mold from the open state, the front ejector plate 8 is pushed back by a return pin (not shown) and moves backward, so that it comes into contact with the cam plate 17 or the release par 12, and the slide claw 15 The rear ejector plate 7 is swung towards the rear ejector plate 7 due to the contact between the tip of the cam plate 17 and the protruding slide claw 15.
The movable mounting plate 6 is moved backward in the direction of approaching the movable mounting plate 6.

Then, when the rear ejector plate 7 comes into contact with the movable mounting plate 6, the cam plate 17
While pushing back against the spring 16, the cam plate 1 is accommodated in the hole 13a of the slide holder 13, and the cam plate 1
7 again engages with the slide pawl 15 to integrally connect the rear ejector plate 7 and the front ejector plate 8 as shown in FIG. 9(a).

(Problems to be Solved by the Invention) By the way, the above conventional lock devices 1.11 all have the following problems:
The elastic force of the springs 5 and 18b is used to release the connection between the two ejector plates 7.8.On the other hand, injection molds are usually used at high temperatures, and under these high temperatures the springs tend to weaken due to creep. (plastic deformation).

As a result, the conventional locking devices 1 and 11 described above have a problem in that the springs 5 and 18b become flattened and the release operation becomes uncertain.

The present invention provides a locking device that advantageously solves this problem with a simple configuration.

(Means for Solving the Problems) A locking device for an ejector plate of an injection molding mold according to the present invention includes a lock pin protruding from a side surface of a front ejector plate and a locking pin that is swingably supported by a side surface of a rear ejector plate. , a locking member that engages and removes the groove from the locking pin by its swing; and a locking member that is fixed to a movable mold plate and comes into contact with the locking member based on the forward movement of the rear ejector plate toward the movable mold plate. a release side cam member that swings the lock member in a direction in which the lock pin is removed from the groove portion; and a release side cam member that is fixed to the movable side mounting plate and causes the rear ejector plate to move backward toward the movable side mounting plate. The present invention is characterized in that it includes a locking side cam member that comes into contact with the locking member and swings the locking member in a direction in which the groove portion and the locking pin engage with each other.

(Function) In an injection mold equipped with such a locking device, when the front ejector plate moves forward in the direction approaching the movable mold plate as the mold opens, the forward movement of the rear ejector plate or the removal of the stripper bolt, etc. Until it is regulated by the regulating means, the latching cam member or the locking member supported on the side surface of the rear ejector plate is placed in a position where its groove engages with the lock pin protruding from the side surface of the front ejector plate. By constraining, the locking device continues to couple the rear ejector plate to the front ejector plate, thereby causing the rear ejector plate to move forward together with the front ejector plate.

When further forward movement of the rear ejector plate is restricted by the restriction means, at the same time, the latching side cam member allows the locking member to swing, and the releasing side cam member locks the locking member from its groove. By swinging the pin in the direction of release, the locking device releases the front ejector plate from the rear ejector plate, and thereafter only the front ejector plate moves further forward.

On the other hand, when closing the mold from the mold open state, the front ejector plate moves backward and comes into contact with the rear ejector plate, and the rear ejector plate also moves backward toward the movable mounting plate, resulting in the above. Conversely, the release side cam member allows the locking member to swing and also swings the locking side cam member or locking member in the direction in which the groove engages with the lock pin, thereby causing the locking device or the rear ejector plate to move. Reconnect to the front ejector plate.

After that, both ejector plates move back together until they come into contact with either the rear ejector plate or the movable mounting plate.

Therefore, according to the locking device of the present invention, the locking member is swung like a positive cam by the releasing side cam member and the locking side cam member without depending on the elastic force of the spring, and the groove of the locking member is rotated. Since the ejector plates are reliably engaged and detached from the lock pin, it is possible to reliably release the coupling between both ejector plates with a simple configuration.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1(a) is a sectional view showing an embodiment of the locking device for an ejector plate of an injection molding mold according to the present invention in a state where it is attached to an injection molding mold, and FIG. 1(b) is a sectional view of the device of the embodiment. FIG. 2 is a side view showing the same parts as in the conventional example, and the same parts as in the conventional example are designated by the same reference numerals.

That is, the injection mold here has a protrusion 19b having a hole 19a serving as an undercut, as shown in FIG.
It is for forming a flat product 19 with a
It includes a movable-side mounting plate 6 and a movable-side template 21 fixed to the movable-side mounting plate 6 via a spacer block 20, and between the movable-side mounting plate 6 and the movable-side template 21. The rear ejector plate 7 and the front ejector plate 8 are supported so as to be horizontally movable between the plates 6 and 21 by guide pins (not shown) fixed to extend, and the movable mounting plate 6 is restricting the forward movement of the rear ejector plate 7 in the separating direction (rightward in the figure) after a predetermined forward position;
A stripper bolt 9 having a shaft portion of a predetermined length that is thicker than the tip threaded portion, and further includes a fixed side mounting plate 22,
Fixed side template 23 fixed to the fixed side mounting plate 22
It is equipped with.

A insert 24 for forming the hole 19a of the product 19 is fitted into the movable template 21 so as to be movable forward and backward.
In addition, each movable template plate 2 is attached to the front ejector plate 8.
The ends of the ejector pin 25 and the return pin 26, which are inserted into the movable mold plate 21 and the front ejector plate 8 so as to move back and forth, are fixed. Connecting pin 27
The insert 24 is fixed thereto.

In addition, lO in the figure penetrates the movable side mounting plate 6 and the rear side ejector plate 7, and the front side ejector plate 8
2 shows an extrusion rod of an injection molding device, which can come into contact with the extrusion rod of the injection molding device;

The locking device 28 of this embodiment installed in such an injection mold is protruded from the side surface of the front ejector plate 8, as shown in an exploded perspective view in FIG. 3 and an enlarged view in FIG. A lock member 33 consisting of a lock pin 29, a lock brake (31) swingably supported on the side surface of the rear ejector plate 7 via a stripper port 30, and a driven pin 32 protruding therefrom, and a movable mold plate. A release side cam block 35 as a release side cam member fixed to the movable side mounting plate 6 via a bolt 34 and a locking side cam as a locking side cam member fixed to the movable side mounting plate 6 via a bolt 36. A block 37 is provided.

Here, the locking member 33 has a groove 31a on the side of the locking plate 31, and the groove 31a is arranged so that the locking member 33 is in a state where the front ejector plate 8 and the rear ejector plate 7 are in close contact with each other. 4th clockwise
When the locking member 33 swings to the predetermined engaged position shown in the figure, it engages with the lock pin 29, and when the locking member 33 swings counterclockwise from the above-mentioned engaged position to the predetermined detached position, it disengages from the lock pin 29.

Further, here, the release side cam block 35 is connected to the movable side template 2.
When the locking member 33 in the engaged position moves forward based on the forward movement of the rear ejector plate 7 toward 1, it has a slope 35a at a position where it comes into contact with the driven pin 32, and the locking member 33 in the detached position moves forward. Then, the side surface 3 is placed in sliding contact with the outer peripheral surface of the driven pin 32.
5b.

On the other hand, the locking side cam block 37 opposes the groove portion 31a of the locking plate 31 when the locking member 33 in the detached position moves backward based on the backward movement of the rear ejector plate 7 toward the movable side mounting plate 6. It has a slope 37a at a position that abuts the side surface 31b, and
When the locking member 33 in the engaged position moves backward, the side surface 3 is brought into sliding contact with the side surface 31b of the lock plate 31.
7b.

In the injection molding mold equipped with such a locking device 28, in the mold clamping state shown in FIG. Due to the close contact with the side surface 37b of the stop-side cam block 37, the locking device 28 is maintained in the above-mentioned engaged position.
Rear ejector plate 7 and front ejector plate 8
are integrally combined.

Then, when opening the mold, from the above state, as shown in Fig. 5 (a)
As shown in the figure, the movable mounting plate 6 moves backward to the left in the figure to open the mold, and first, a part of the sprue of the product 19 is pulled out from the fixed mold plate 23, and the product 19 and the insert 24 are separated. At this stage, the locking member 33 is still maintained in the engaged position as shown in FIG. 5(b).

Next, as shown in FIG. 6(a), the extrusion rod 10
Or, by moving forward to the right, the rear ejector plate 7 moves forward in the direction approaching the front ejector plate 8 or the movable mold plate 21 pressed by its tip.
Until the forward movement of the stripper holder 9 is regulated by contact between the head of the stripper holder 9 and the bottom of the counterbore of the movable mounting plate 6,
The above-mentioned engagement posture is maintained by sliding contact between the locking member 33 or the side surface 31b of the locking plate 31 and the side surface 37b of the locking side cam block 37, and the locking device 28 moves the rear ejector plate 7 to the front ejector plate 8. Continue to bond reliably. Therefore, during this period, it moves forward together with the rear ejector plate 7 or the front ejector plate 8, thereby pushing out the ejector pin 25 or the product 19 from the cavity of the movable mold plate 21, and the insert 24 moves forward. The product 19 advances from the movable mold plate 21 while being fitted into the hole 19a of the product 19.

When the further forward movement of the rear ejector plate 7 is restricted by the stripper bolt 9, substantially at the same time, as shown in FIG. By allowing the locking member 33 to swing when the locking member 33 comes off the cam block 35 and swinging the locking member 33 toward the detached position due to the contact between the release side cam block 35 or its slope 35a and the driven pin 32, The lock device 28 releases the front ejector plate 8 from the rear ejector plate 7, and thereafter, as shown in FIG. 7(b), the release side cam block 35
Alternatively, the lock member 33 is maintained in the detached position by sliding contact between the side surface 35b and the outer peripheral surface of the driven pin 32, and the lock pin 29 is moved back from the lock plate by the backward movement of the front ejector plate 8 during mold clamping, which will be described later. 31 groove portion 31a
Let it go inside. Therefore, after the front ejector plate 8 is released, the rear ejector plate 7 stops and only the front ejector plate 8 moves further forward, as shown in FIG.
5, the product 19 is removed from the insert 24 and discharged from the mold.

On the other hand, when closing the mold from the mold open state, as the extrusion rod 10 retreats, the return pin 26 or its tip is pushed back by contact with the stationary mold plate 23.
When the front ejector plate 8 moves backward and comes into contact with the rear ejector plate 7, and thereby the rear ejector plate 7 also moves backward together with the front ejector plate 8 toward the movable mounting plate 6, contrary to the above, The driven pin 32 comes off the side surface 35b of the release-side cam block 35, allowing the release-side cam block 35 or the locking member to swing, and the latching-side cam block 37, its slope 37a, and the side surface 31b of the lock plate 31. The locking device 28 or the rear ejector plate 7 is reconnected to the front ejector plate 8 by swinging the locking member 33 toward the engaged position upon contact with the locking member 33 .

Note that while the rear ejector plate 7 is moving backward until it comes into contact with the front ejector plate 8 or the rear ejector plate 7, the rear ejector plate 7 is in sliding contact with the pushing rod 10 that is moving backward and the rear ejector plate 7, and the front ejector plate 8 The sliding contact between the rear ejector plate 7 and the coupling pin 27 forces the rear ejector plate 7 backward, or the urging force is usually sufficiently smaller than the holding force caused by the close sliding contact between the rear ejector plate 7 and the guide pin (not shown). During this time, the plate 7 is held at the forward limit position.

After that, both ejector plates 7.8 come into contact with the rear ejector plate 7 or the movable mounting plate 6.
During this time, the locking member 33 or the locking device 28 or the front ejector plate is maintained in the engaging posture by sliding contact between the side surface 31b of the lock plate 31 and the side surface 37b of the locking side cam block 37. 8 and continue to securely connect the rear ejector plate 7 to the rear ejector plate 7.

Therefore, according to the locking device 28 of this embodiment, the locking member 33 can be swung like a positive cam by the release side cam block 35 and the locking side cam block 37 without depending on the elastic force of the spring. By reliably engaging and removing the groove portion 31a of the locking member 33 with respect to the locking pin 29, the connection between both ejector plates 7.8 can be reliably released with a simple configuration.

Although the present invention has been described above based on the illustrated example, the present invention is not limited to the above-mentioned example. 7 and the movable mounting plate 6 to bias the rear ejector plate 7 in the forward direction, and a spring fixed to the side surface of the front ejector plate 8 to be driven similarly to the release side cam block 35. A front ejector play which is in sliding contact with the outer peripheral surface of the pin 32;
Another cam member or the like may be further provided to maintain the locking member 33 in the detached position until the rear ejector plate 7 comes into contact with the rear ejector plate 7, and to release the locking member 33 at the time of contact.

(Effects of the Invention) Thus, according to the locking device of the present invention, the locking member is swung like a positive cam by the release side cam member and the locking side cam member, without relying on the elastic force of the spring. Since the groove portion of the lock member is reliably engaged with and removed from the lock pin, it is possible to reliably release the coupling between the front ejector plate and the rear ejector plate with a simple configuration.

[Brief explanation of the drawing]

1(a) and 1(b) are a sectional view and a side view showing an embodiment of the locking device for an ejector plate of an injection molding mold according to the present invention in a state where it is attached to an injection molding mold, and FIG. 2 is the above-mentioned FIG. 3 is an exploded perspective view showing the configuration of the device of the above embodiment; FIG. 4 shows the device of the above embodiment in the closed state of the injection mold. An enlarged side view, FIGS. 5 to 7 are operational explanatory diagrams showing the operation of the apparatus of the above embodiment and the injection mold equipped with the same in different states, and FIG. 8 is a conventional locking device. 9 to 11 are operational explanatory diagrams showing the operation of the conventional device and the injection mold equipped with it in different states, and FIG. 12(a) to (c) are other FIG. 13 is a cross-sectional view showing a ball plunger used in the other conventional device. 6...Movable side mounting plate 7...Rear side ejector plate 8...Front side ejector plate 21...Movable side template plate 28...Lock device 2
9...Lock pin 31a...Groove portion 33...
・Lock member 35...Release side cam block 3
7... Latching side cam block Fig. 1 (a) (b) Fig. 2 qh Fig. 4 Fig. 5 (b) Fig. 6 (a) (b) Fig. 7 (a) (b) Fig. Figure 9 (a) (b) Ryogawa map (a) (b) Figure 11 (a) (b) @ Figure 12 (a) (b) Figure 13 Procedure Amendment (method) % formula % 1, Display of the case: 1990 Patent Application No. 303968 2, Name of the invention: Injection mold ejector plate locking device 3, Person making the amendment Relationship to the case: Patent applicant (399) Nissan Motor Co., Ltd. 4, Agent Person 6, subject of amendment "Brief explanation of drawings" column ■ of the specification, "Figures 12 (a) to (C)" in the second line of page 23 of the specification
is corrected to "Fig. 12(a)-(b)".

Claims (1)

[Scope of Claims] 1. A lock pin (29) protruding from the side surface of the front ejector plate (8) and a lock pin (29) that is swingably supported on the side surface of the rear ejector plate (7), so that the lock pin (29) projects from the side surface of the front ejector plate (8). The groove portion (31
a), a locking member (33) for attaching and detaching the movable side template (
21), which is fixed to the movable side mold plate and comes into contact with the locking member based on the forward movement of the rear ejector plate toward the movable side mold plate, and swings the locking member in the direction in which the locking pin is removed from the groove. Side cam member (35)
is fixed to the movable side mounting plate (6), and comes into contact with the locking member based on the backward movement of the rear ejector plate toward the movable side mounting plate, and the groove portion and the locking pin engage the locking member. A locking device for an ejector plate of an injection mold, comprising: a locking side cam member (37) that swings in a direction to move the ejector plate of an injection mold.