CN218557860U - Injection mold - Google Patents

Abstract

The utility model provides an injection mold, include: the device comprises a cavity, a pouring gate communicated with the cavity and an exhaust insert for exhausting gas in the cavity; wherein the exhaust passage of the exhaust insert is progressively expanded in size along the gas exhaust direction. The utility model provides an among the injection mold, the size that sets up exhaust passage progressively expands along the gas outgoing direction for along the area of ventilating of gas outgoing direction exhaust mold insert crescent, effectively increased the displacement, and accelerated gas outgoing's speed, thereby reduce the influence of stranded gas phenomenon greatly, help improving the weld line intensity of miniature injection molding and the percentage elongation of part.

Description

Injection mold

Technical Field

The utility model relates to a parts machining technical field, in particular to injection mold.

Background

With the development of technology, micro injection molded parts with a weight of only a few milligrams become more and more important, and particularly in the fields of automobiles, electronics, medical treatment and the like, the requirements of the micro injection molded parts gradually rise, and meanwhile, the quality requirements and the process requirements on the micro injection molded elements are higher and higher. For example, a micro injection molding part is arranged in a high-pressure fuel injector of an automobile, the diameter of the micro injection molding part is smaller than 10mm, the micro injection molding part is a key part used for supporting an O-shaped sealing ring in the high-pressure fuel injector to ensure the sealing performance of the O-shaped sealing ring, when the fuel injector works, the micro injection molding part is easy to deform under the action of oil pressure, and the micro injection molding part needs to have better strength and elongation at the moment.

Because the volume is less, the miniature injection molding piece is generally molded by adopting a single-point injection molding mode, and the molding mode has higher requirements on the mold. For example, fig. 1 shows a schematic view of a conventional injection mold, which includes a cavity 200, and a gate 300 and a vent 100 disposed at both sides of the cavity 200. During production, the molten material flows into the cavity 200 through the gate 300 and joins near the position of the vent hole 100 until the part is molded, and the air in the cavity 200 is gradually discharged from the vent hole 100 as the material flows in. At this time, a weld line of the micro injection molded part is formed at a position where the materials meet, i.e., at the exhaust hole 100.

Generally, in the micro injection molded part, the mechanical strength of the weld line region is generally lower than that of the non-weld line region, which affects the strength and elongation of the whole part, and the weld line is easy to crack, thereby causing the part to be scrapped. Therefore, how to improve the weld line strength of the micro injection molded parts is an important problem. Wherein, influence a leading reason of the weld line intensity of miniature injection molding spare is that current injection mold is in process of production, and the easy emergence is stranded gas phenomenon in weld line position department, and the air in the die cavity can not effectively be discharged promptly for weld line position department takes place to lack the material or produces phenomenons such as bubble.

Disclosure of Invention

An object of the utility model is to provide an injection mold to in the production process of the miniature injection molding among the solution prior art, take place the problem of stranded gas and then lead to weld line intensity reduction in weld line position department.

In order to solve the technical problem, the utility model provides an injection mold, include: the mold comprises a cavity, a pouring gate communicated with the cavity and a gas exhaust insert for exhausting gas in the cavity, wherein the size of a gas exhaust channel of the gas exhaust insert is gradually expanded along the gas exhaust direction.

Optionally, the size of the exhaust passage of the exhaust insert increases in a gradient along the gas exhaust direction; alternatively, the exhaust passage size of the exhaust insert increases continuously along the gas exhaust direction.

Optionally, the exhaust insert includes two inserts that are symmetrical and laminate each other, be provided with the exhaust groove on the binding face of insert to laminate mutually by the exhaust groove on two inserts and form the exhaust passage.

Optionally, the exhaust grooves include a first exhaust groove and a second exhaust groove sequentially arranged along the gas exhaust direction, the first exhaust grooves on the two inserts are attached to form a first exhaust channel, and the second exhaust grooves on the two inserts are attached to form a second exhaust channel.

Optionally, the width dimension of the first exhaust groove is smaller than the width dimension of the second exhaust groove; and/or the length dimension of the first exhaust groove is smaller than that of the second exhaust groove.

Optionally, the width of the first exhaust groove is less than or equal to 0.01mm.

Optionally, the exhaust groove is located in a middle area of the abutting surface of the insert.

Optionally, the section of the exhaust passage of the exhaust insert is square, rectangular or trapezoidal.

Optionally, the exhaust insert is disposed opposite to the gate.

Optionally, an exhaust structure is further disposed in a region between the sprue gate and the exhaust insert on the cavity.

The utility model provides an among the injection mold, the size of the exhaust passage of the exhaust mold insert of setting on the die cavity progressively expands along the gas outgoing direction for along the area of ventilating of the exhaust mold insert of gas outgoing direction crescent, effectively increased the displacement, and accelerated gas outgoing's speed, thereby reduce the influence of the gas trapping phenomenon greatly, help improving the weld line intensity of miniature injection molding and the percentage elongation of part.

Drawings

FIG. 1 is a schematic view of a conventional injection mold;

fig. 2 is a schematic structural diagram of an injection mold according to an embodiment of the present invention;

fig. 3 is a schematic structural view of an exhaust insert according to an embodiment of the present invention.

Detailed Description

As described in the background art, in the process of producing a micro injection molded part, a trapping phenomenon easily occurs at a weld line position of an existing injection mold, which results in that the weld line strength of the finally formed injection molded part is low, and a crack phenomenon of the weld line is easily generated, thereby causing the part to be scrapped. The utility model provides an injection mold, the size of the exhaust passage of the exhaust mold insert of setting on the die cavity progressively expands along the gas outgoing direction for along the area of ventilating of the exhaust mold insert of gas outgoing direction crescent, effectively increased the displacement, and accelerated gas outgoing's speed, thereby reduce the influence of the stranded gas phenomenon greatly.

The following provides a further detailed description of an injection mold according to the present invention with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in simplified form and are not to precise scale, and are provided for convenience and clarity in order to facilitate the description of the embodiments of the present invention.

Fig. 2 is a schematic structural view of an injection mold according to an embodiment of the present invention. As shown in fig. 2, the injection mold provided in this embodiment includes: the mold comprises a cavity 200, a sprue 300 communicated with the cavity 200, and an exhaust insert 400 for exhausting gas in the cavity, wherein the exhaust insert 400 is arranged on the cavity 200 at a position corresponding to a welding line, namely opposite to the sprue 300. Wherein the exhaust passages of the exhaust insert 400 are progressively expanded in size along the gas exhaust direction. The ventilation area of the exhaust channel along the gas exhaust direction is gradually increased, the exhaust volume is effectively increased, and the gas exhaust speed is accelerated, so that the influence of the trapping phenomenon is greatly reduced, and the improvement of the weld line strength of the micro injection molding part and the elongation of the part are facilitated.

Specifically, as shown in fig. 2, the cavity 200 is, for example, a ring-shaped structure, and includes an outer sidewall 210, an inner sidewall 220, and a bottom 230, forming a semi-closed cavity, and an opposite side of the bottom 230 is an opening of the cavity 200. The gate 300 is located on the outer sidewall 210 or the bottom 230 of one side of the cavity 200, and the gas exhaust insert 400 is embedded on the outer sidewall 210 of the cavity 200 and is disposed opposite to the gate 300. In this embodiment, the cavity 200 is a movable mold.

Meanwhile, the injection mold provided by the embodiment further comprises a static mold opposite to the cavity 200, and one surface of the static mold facing the cavity 200 is a parting surface 500. The parting surface 500 is, for example, a plane, and has a shape and a size matching those of the opening of the cavity 200. In the actual production process, the cavity 200 moves towards the stationary mold, so that the opening is attached to the parting surface 500 of the stationary mold, and a closed cavity is formed, and the shape of the closed cavity is the same as that of the cavity 200. Then, a manufacturing material is injected into the closed cavity through the gate 300 to form an injection molding having the same shape as the cavity of the cavity 200. After the injection molding is finished, the cavity 200 is separated from the parting surface 500 of the static mold, and after the cavity is returned to the original position, the molded injection molding piece can be separated from the opening of the cavity 200.

In other embodiments, a venting structure may be added to the cavity 200 in a region between the sprue 300 and the venting insert 400. In this embodiment, the center point of the cavity 200 is used as an origin, the position of the sprue gate 300 is 0 °, and the exhaust insert 400 is disposed at a position of 180 °, for example, an exhaust structure may be additionally disposed at positions of 90 ° and 270 °, so as to further increase the amount of exhaust, thereby further reducing the influence of air trapping. Wherein, the exhaust structure is an exhaust hole or an exhaust insert, for example.

Fig. 3 is a schematic structural view of an exhaust insert according to an embodiment of the present invention. As shown in fig. 3, the exhaust insert 400 includes two inserts 410 which are symmetrical and attached to each other, the attachment surfaces of the inserts 410 are provided with exhaust grooves 420, and the exhaust channels are formed by attaching the exhaust grooves 420 of the two inserts. The material of the exhaust insert 400 is the same as that of the cavity 200, and for example, a mold steel material is used. In other embodiments, the degassing insert 400 may be a material having a hardness slightly lower than the hardness of the cavity 200.

With continued reference to fig. 3, the exhaust grooves 420 include a first exhaust groove 421 and a second exhaust groove 422 sequentially arranged along the gas exhaust direction, the first exhaust grooves 421 of the two inserts 410 are attached to form the first exhaust channel, and the second exhaust grooves 422 of the two inserts 410 are attached to form the second exhaust channel. That is, in this embodiment, the exhaust passage includes a first exhaust passage and a second exhaust passage arranged in sequence along the gas exhaust direction, so that the gas in the cavity 200 flows through the first exhaust passage and is exhausted from the second exhaust passage.

Further, the cross-section of the exhaust channel of the exhaust insert 400 is square, rectangular or trapezoidal. That is, the first exhaust passage or the second exhaust passage has a square, rectangular, or trapezoidal cross section in a cross section perpendicular to the gas discharge direction. As shown in fig. 3, the first exhaust groove 421 or the second exhaust groove 422 has a square, rectangular, or trapezoidal cross section in a cross section parallel to the XZ plane. In the present embodiment, the cross section of the first exhaust groove 421 is, for example, a rectangle in a cross section parallel to the XZ plane, and the cross section of the first exhaust passage formed is also a rectangle. Then, in the XZ plane, the first exhaust passage has a long slit shape. Compared with a circular exhaust hole, the ventilation area is increased (namely, when the diameter of a circle is the same as the side length of a square, the side length of a short side of a rectangle or the height of a trapezoid, the area of the circle is smaller), so that the exhaust volume of the first exhaust channel is increased, and the influence of the trapped air phenomenon is favorably reduced.

Meanwhile, the exhaust insert 400 is provided in the present embodiment with a gradient of increasing exhaust passage size along the gas exhaust direction; alternatively, the exhaust passage size of the exhaust insert continuously increases along the gas exhaust direction such that the exhaust passage size of the exhaust insert 400 gradually expands along the gas exhaust direction. Specifically, as shown in fig. 3, the width dimension of the first exhaust groove is smaller than the width dimension of the second exhaust groove; and/or the length dimension of the first exhaust groove is smaller than that of the second exhaust groove. That is, in the X direction, the size of the first exhaust groove 421 is smaller than the size of the second exhaust groove 422; and/or, in the Z direction, the size of the first exhaust groove 421 is smaller than the size of the second exhaust groove 422.

In this embodiment, for example, the width of the first exhaust groove 421 is smaller than the width of the second exhaust groove 422, the length of the first exhaust groove 421 is the same as the length of the second exhaust groove 422, and the cross sections of the first exhaust groove 421 and the second exhaust groove 422 are both rectangular, that is, the exhaust grooves are arranged in a step shape. In other embodiments, the width and length of the first exhaust groove 421 may be smaller than the width and length of the second exhaust groove 422. Therefore, the ventilation area of the second exhaust channel formed in the exhaust insert is larger than that of the first exhaust channel, so that gas is rapidly exhausted out of the cavity, and air resistance in the first exhaust channel is avoided. That is, in this embodiment, set up first exhaust passage and second exhaust passage in the exhaust mold insert, gas is earlier by the even discharge of first exhaust passage, is discharged gas fast by the great second exhaust passage of area of ventilating again, has effectively increased the displacement, and has accelerated gas outgoing's speed to reduce greatly and be stranded the influence of gas phenomenon.

Further, the width of the first exhaust groove 421 is not more than 0.01mm. Meanwhile, for example, the width dimension of the second exhaust groove 422 is set to 0.02mm or less. In the present embodiment, for example, the width dimension of the first exhaust groove 421 and the width dimension of the second exhaust groove 422 are set to 0.005mm and 0.01mm, respectively, that is, the width dimension of the first exhaust passage and the width dimension of the second exhaust passage are set to 0.01mm and 0.02mm, respectively. Because the size of miniature plastic part is less, then the size of exhaust mold insert is also corresponding less, through the width of the exhaust passageway in the restriction exhaust mold insert in this embodiment, especially the width of first exhaust passageway for prevent to take place the flash phenomenon, with the aesthetic property of assurance injection molding outward appearance.

Meanwhile, the air vent groove 420 is located in a middle region of the abutment surface of the insert 410. Specifically, as shown in fig. 3, along the Z direction, neither the first exhaust groove 421 nor the second exhaust groove 422 penetrates through the insert 410, so as to prevent the occurrence of flash and ensure the aesthetic appearance of the injection molded part. In this embodiment, for example, in the Z direction, the vent groove 420 is provided in a region of 1/3 to 2/3 of the abutment surface of the insert 410.

Further, the depth dimension of the first exhaust groove 421 is smaller than the depth dimension of the second exhaust groove 422. That is, in the Y direction, the size of the first exhaust groove 421 is smaller than the size of the second exhaust groove 422. In this embodiment, for example, the depth of the second exhaust groove 422 is twice as large as the depth of the first exhaust groove 421. Therefore, the flowing time of the gas in the first exhaust channel can be reduced, the exhaust speed of the gas is accelerated, and the influence of the gas trapping phenomenon is reduced.

To sum up, the utility model provides an injection mold sets up the exhaust passage's of the exhaust mold insert on the die cavity size and gradually expands along the gas outgoing direction for along the area of ventilating of the exhaust mold insert of gas outgoing direction crescent, effectively increased the displacement, and accelerated gas outgoing's speed, thereby reduce the influence of the trapping gas phenomenon greatly, help improving the weld line intensity of miniature injection molding and the percentage elongation of part.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. An injection mold, comprising: the mold comprises a cavity, a pouring gate communicated with the cavity and a gas exhaust insert for exhausting gas in the cavity, wherein the size of a gas exhaust channel of the gas exhaust insert is gradually expanded along the gas exhaust direction.

2. The injection mold of claim 1, wherein the vent passages of the vent insert increase in size in a gradient along a gas venting direction; alternatively, the exhaust passage size of the exhaust insert increases continuously along the gas exhaust direction.

3. The injection mold of claim 1, wherein the venting insert comprises two inserts that are symmetrical and abut each other, and the abutting surfaces of the inserts are provided with venting grooves, and the venting channels are formed by the abutting surfaces of the two inserts.

4. The injection mold of claim 3, wherein the vent grooves comprise a first vent groove and a second vent groove arranged in sequence along a gas discharge direction, the first vent grooves of the two inserts fit together to form a first vent channel, and the second vent grooves of the two inserts fit together to form a second vent channel.

5. The injection mold of claim 4, wherein a width dimension of the first vent groove is less than a width dimension of the second vent groove; and/or the length dimension of the first exhaust groove is smaller than that of the second exhaust groove.

6. The injection mold of claim 4, wherein the width dimension of the first exhaust groove is 0.01mm or less.

7. The injection mold of claim 3, wherein the vent groove is located in a middle region of the abutment surface of the insert.

8. The injection mold of claim 1, wherein the vent passages of the vent insert are rectangular or trapezoidal in cross-section.

9. The injection mold of claim 1, wherein the vented insert is disposed opposite the gate.

10. The injection mold of claim 1, wherein a vent structure is further provided in the cavity in a region between the gate and the vent insert.

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