Quickly-cooling and rapidly-heating mold for compression molding of graphite bipolar plate

Abstract

The utility model belongs to the technical field of bipolar plate production, and provides a rapid cooling and rapid heating mold for compression molding of a graphite bipolar plate, which comprises a mold plate arranged on the upper side and / or the lower side of the bipolar plate, and the mold plate comprises a first mold sheet, a second mold sheet and a third mold sheet which are sequentially arranged, a disc-shaped heating wire is arranged between the first mold piece and the second mold piece, a closed diffusion channel is arranged between the second mold piece and the third mold piece, and an air inlet pipe and an exhaust pipe are arranged on the third mold piece. Wherein the air inlet pipe is communicated with the middle of the diffusion channel, and the exhaust pipe is communicated with the edge of the diffusion channel, so that a gas medium flows in the mold through the air inlet pipe, the diffusion channel and the exhaust pipe in sequence; a gas medium with good safety is adopted as a refrigerant, the diffusion channel is utilized to enable the gas medium to be uniformly and rapidly diffused, and the temperature change uniformity of the mold is good.

Description

Technical Field

[0001] The utility model relates to the technical field of bipolar plate compression molding, in particular to a rapid cooling and heating mold for compression molding of graphite bipolar plates. Background Art

[0002] According to different materials, bipolar plates can be divided into graphite bipolar plates, metal bipolar plates and composite bipolar plates. Graphite has good chemical stability and conductivity, but poor air tightness. Metals such as stainless steel and titanium alloy have good conductivity and heat dissipation, and can also be used as raw materials for bipolar plates, but because the technology itself has weak corrosion resistance, it is necessary to increase its corrosion resistance by coating the metal surface.

[0003] In order to solve the problems of high processing costs and large-scale production, researchers began to use compression molding to manufacture bipolar plates. First, a mixture of graphite powder and resin is prepared, and then the mixture and the mold are pre-treated. The melting temperature of the polymer and a certain pressure are used to make the powder flow in the mold and fill the entire cavity. After curing and demolding, the bipolar plate is obtained. If the binder is a thermosetting plastic, it generally only takes a few minutes to cure and demold; if the binder used is a thermoplastic plastic, the mold needs to be cooled to a temperature below the melting point of the binder before demolding.

[0004] Therefore, in order to meet the temperature difference requirements during the bipolar plate molding process and take into account the protection of the mold, the mold needs to have rapid cooling and heating functions.

[0005] Although molds with rapid cooling and heating effects have appeared in the prior art, due to unreasonable selection of the medium and design of the medium flow path, the mold experiences slow local cooling, which affects the curing and demolding effect of the bipolar plate. Utility Model Content

[0006] The utility model aims to provide a rapid cooling and heating mold for graphite bipolar plate compression molding, which adopts a safe gas medium as a refrigerant, utilizes a diffusion channel to make the gas medium diffuse evenly and quickly, and has good uniformity in mold temperature change.

[0007] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0008] A rapid cooling and heating mold for compression molding of a graphite bipolar plate, comprising a template arranged on the upper side and / or the lower side of the bipolar plate, the template comprising a first die sheet, a second die sheet and a third die sheet arranged in sequence, a disc-shaped heating wire is arranged between the first die sheet and the second die sheet, a closed diffusion channel is arranged between the second die sheet and the third die sheet, and an intake pipe and an exhaust pipe are arranged on the third die sheet;

[0009] The air inlet pipe is connected to the middle of the diffusion channel, and the exhaust pipe is connected to the edge of the diffusion channel, so that the gas medium flows in the mold through the air inlet pipe, the diffusion channel and the exhaust pipe in sequence.

[0010] Furthermore, the diffusion channel includes a plurality of straight channels and a plurality of annular channels, and the plurality of straight channels intersect at one point, and the intersection point is the channel center;

[0011] The plurality of annular channels are arranged concentrically with the channel center as the circle center, so that any of the linear channels are connected to the plurality of annular channels respectively, and the point where the end of the linear channel is connected to the annular channel with the largest diameter is the channel edge;

[0012] Wherein, the air inlet pipe is connected to the center of the channel, and the exhaust pipe is connected to the edge of the channel.

[0013] Furthermore, the corresponding surfaces of the first mold piece and the second mold piece are respectively provided with spiral grooves, the heating wire is hidden in the spiral grooves, and the first mold piece and the second mold piece are fixed by welding.

[0014] Furthermore, the heating wire connector of the heating wire extends outside the second mold piece.

[0015] Furthermore, the third mold piece is fixedly connected to the second mold piece by fixing bolts.

[0016] Furthermore, a sealing gasket is provided between the third die and the second die.

[0017] Furthermore, a flange is provided on the surface of the third mold piece away from the second mold piece. Beneficial Effects

[0018] The present application firstly adopts a gas medium as a refrigerant, enters from the center of the diffusion channel, and evenly diffuses to the surroundings in a ring shape, so that the gas medium is evenly diffused to the surroundings, and finally leaves from the edge of the channel, thereby reducing the local curing demoulding effect of the bipolar plate affected by the uneven diffusion of the medium;

[0019] The gas medium moves in a closed diffusion channel, which is safe.

[0020] The gas medium only flows on one side of the second mold piece, and the heating wire is closer to the bipolar plate to ensure the heating effect of the heating wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1It is a cross-sectional schematic diagram of the utility model;

[0023] Figure 2 yes Figure 1 A partial enlarged view of the middle part;

[0024] Figure 3 is a top view of the second die.

[0025] In the figure: 100-template, 200-bipolar plate, 110-first mold piece, 120-second mold piece, 121-diffusion channel, 1211-straight channel, 1212-annular channel, 1213-channel center, 1214-channel edge, 1215-threaded hole, 130-third mold piece, 140-heating wire, 141-heating wire joint, 150-intake pipe, 160-exhaust pipe, 170-fixing bolt, 180-sealing gasket, 190-flange. DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0027] like Figure 1-3 As shown, the present application proposes a rapid cooling and heating mold for compression molding of graphite bipolar plates, including a template 100 arranged on the upper side and / or lower side of the bipolar plate 200, the template 100 includes a first mold sheet 110, a second mold sheet 120 and a third mold sheet 130 arranged in sequence, a disc-shaped heating wire 140 is arranged between the first mold sheet 110 and the second mold sheet 120, a closed diffusion channel 121 is arranged between the second mold sheet 120 and the third mold sheet 130, and an intake pipe 150 and an exhaust pipe 160 are arranged on the third mold sheet 130; wherein the intake pipe 150 is connected to the middle of the diffusion channel 121, and the exhaust pipe 160 is connected to the edge of the diffusion channel 121, so that the gas medium flows in the mold through the intake pipe 150, the diffusion channel 121, and the exhaust pipe 160 in sequence.

[0028] During the compression molding process of the bipolar plate, the two first mold sheets 110 are brought close to each other, and finally a mold cavity (not shown) is formed between the grooves of the two first mold sheets 110 , and the powder flows in the mold cavity and solidifies into a mold.

[0029] In a specific embodiment, the gas medium is air, and after being discharged from the exhaust pipe 160, the gas medium enters the refrigeration system for cooling, and the low-temperature gas medium then enters the mold from the intake pipe 150; first, when rapid heating is required, the heating wire 140 is powered on to generate heat to exchange heat with the first mold piece 110 to achieve mold preheating or heating of the bipolar plate; secondly, when rapid cooling is required, the low-temperature gas medium enters the diffusion channel 121, and evenly radiates outward from the middle of the diffusion channel 121 to the edge of the diffusion channel 122, and finally is discharged from the exhaust pipe 160, so that the temperature of the first mold piece 110 changes evenly, avoiding the problem of large local temperature difference in the mold affecting the curing and demolding effect of the bipolar plate.

[0030] Since the gas medium enters and exits the mold above the mold, it no longer occupies the lateral space of the mold. The connection space between the mold and the lifting mechanism in the equipment can be shared to avoid protruding structures interfering with other components.

[0031] The third mold piece 130 is used to seal the diffusion channel 121 . When manufacturing the mold, it is only necessary to make grooves on the surface of the second mold piece 120 , and the mold manufacturing is simple.

[0032] Due to the active chemical properties of water, after it comes into contact with graphite, it will completely destroy the harmful elements and impurities in the chemical composition, resulting in a decrease in the quality of graphite. In addition, the processing of graphite by water will also cause some quality problems. Since graphite easily absorbs water, after processing with water, the graphite absorbs excessive water inside, which is slow and difficult to dry, resulting in a long processing cycle; therefore, in this embodiment, a gas medium is used to meet the drying environment while avoiding affecting the quality of the graphite bipolar plate.

[0033] In the present application, the specific structure of the diffusion channel 121 is as follows: the diffusion channel 121 includes a plurality of straight channels 1211 and a plurality of annular channels 1212, and the plurality of straight channels 1211 intersect at one point, and the intersection point is the channel center 1213; the plurality of annular channels 1212 are concentrically arranged with the channel center 1213 as the center of the circle, so that any straight channel 1211 is respectively connected to a plurality of annular channels 1212, and the end of the straight channel 1211 is connected to the annular channel 1212 with the largest diameter as the channel edge 1214; wherein the intake pipe 150 is connected to the channel center 1213, and the exhaust pipe 160 is connected to the channel edge 1214.

[0034] As a specific embodiment of the present application, the number of straight channels 1211 is two, the number of annular channels 1212 is four, and thus the number of channel edges 1214 is four, and four exhaust pipes 160 are correspondingly arranged on the third mold piece 130; the gas medium flowing from the channel center 1213 vertically to the second mold piece 120 diffuses uniformly along the surface of the second mold piece 120 from the channel center 1213 to the surrounding areas until it fills the straight channel 1211 and the annular channel 1212, and finally flows out from the channel edge 1214, thereby realizing uniform and rapid diffusion of the gas medium, and then realizing uniform cooling of the second mold piece 120.

[0035] As a specific embodiment of the present application, the air intake pipe 150, the exhaust pipe 160 and the third mold piece 130 are an integrally formed structure, which improves the air tightness of the air intake pipe 150 and the exhaust pipe 160 and prevents leakage of the gas medium.

[0036] In the present application, spiral grooves are respectively provided on the corresponding surfaces of the first mold piece 110 and the second mold piece 120, and the heating wire 140 is hidden in the spiral grooves. Meanwhile, the first mold piece 110 and the second mold piece 120 are fixed by welding.

[0037] The straight channel 1211 and the annular channel 1212 simulate the spiral path of the heating wire, and can first cool the heating wire 140 and the portion of the first mold piece 110 corresponding to the heating wire 140 to reduce the excessive local temperature difference of the first mold piece 110 caused by the distance difference.

[0038] In the present application, in order to ensure the connection between the heating wire 140 and an external power source or control system, the heating wire connector 141 of the heating wire 140 extends outside the second mold piece 120 .

[0039] In the present application, the third mold piece 130 is fixedly connected to the second mold piece 120 via fixing bolts 170 ; by disassembling the third mold piece 130 , the diffusion channel 121 can be cleaned of dust and impurities to achieve a clearing effect.

[0040] Furthermore, in order to avoid leakage of gas medium due to the presence of a contact gap between the second mold piece 120 and the third mold piece 130, a sealing gasket 180 is arranged between the third mold piece 130 and the second mold piece 120; it should be noted that the sealing gasket should reserve holes corresponding to the intake pipe 150 and the exhaust pipe 160, and at the same time reserve holes for the fixing bolts 170 to pass through.

[0041] Furthermore, a plurality of threaded holes 1215 are arranged in a ring shape on the surfaces of the second mold piece 120 and the third mold piece 130 that match each other, and the third mold piece 130 and the second mold piece 120 are fixedly connected by screwing a plurality of fixing bolts 170 into the plurality of threaded holes 1215 .

[0042] In the present application, in order to facilitate the hoisting and lifting of the third mold piece 130 , a flange 190 is provided on the surface of the third mold piece 130 away from the second mold piece 120 .

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A rapid cooling and heating mold for compression molding of a graphite bipolar plate, comprising a mold plate (100) arranged on the upper side and / or the lower side of the bipolar plate (200), characterized in that: The template (100) comprises a first mold piece (110), a second mold piece (120) and a third mold piece (130) arranged in sequence, a disc-shaped heating wire (140) is arranged between the first mold piece (110) and the second mold piece (120), a closed diffusion channel (121) is arranged between the second mold piece (120) and the third mold piece (130), and an air intake pipe (150) and an exhaust pipe (160) are arranged on the third mold piece (130); The air inlet pipe (150) is connected to the middle of the diffusion channel (121), and the exhaust pipe (160) is connected to the edge of the diffusion channel (121), so that the gas medium flows in the mold through the air inlet pipe (150), the diffusion channel (121), and the exhaust pipe (160) in sequence.

2. The rapid cooling and heating mold for compression molding of graphite bipolar plates according to claim 1, characterized in that: The diffusion channel (121) comprises a plurality of straight channels (1211) and a plurality of annular channels (1212); the plurality of straight channels (1211) intersect at one point, and the intersection point is the channel center (1213); The plurality of annular channels (1212) are arranged concentrically with the channel center (1213) as the circle center, so that any one of the linear channels (1211) is connected to the plurality of annular channels (1212), and the point where the end of the linear channel (1211) is connected to the annular channel (1212) with the largest diameter is the channel edge (1214); The air inlet pipe (150) is connected to the center of the channel (1213), and the exhaust pipe (160) is connected to the edge of the channel (1214).

3. The rapid cooling and heating mold for compression molding of graphite bipolar plates according to claim 2, characterized in that: Corresponding surfaces of the first mold piece (110) and the second mold piece (120) are respectively provided with spiral grooves, the heating wire (140) is hidden in the spiral grooves, and the first mold piece (110) and the second mold piece (120) are fixed by welding.

4. The rapid cooling and heating mold for compression molding of graphite bipolar plates according to claim 3, characterized in that: The heating wire connector (141) of the heating wire (140) extends outside the second mold piece (120).

5. The rapid cooling and heating mold for compression molding of graphite bipolar plates according to claim 2, characterized in that: The third mold piece (130) is fixedly connected to the second mold piece (120) via a fixing bolt (170).

6. The rapid cooling and heating mold for compression molding of graphite bipolar plates according to claim 5, characterized in that: A sealing gasket (180) is provided between the third mold piece (130) and the second mold piece (120).

7. The rapid cooling and heating mold for compression molding of graphite bipolar plates according to any one of claims 1 to 6, characterized in that: A flange (190) is provided on a surface of the third mold piece (130) away from the second mold piece (120).

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