Phenolic plastic spherical handle mold structure and molding method

Abstract

The invention relates to the technical field of aviation non-metal material forming, in particular to a phenolic plastic spherical handle mold structure and a forming machining method.The phenolic plastic spherical handle mold structure structurally comprises an upper mold core, an upper mold, a sleeve, a middle mold core, a middle mold plate, a lower mold and a lower mold core, and the upper mold and the lower mold are correspondingly arranged on the upper portion and the lower portion in the sleeve respectively; the middle mold plate is arranged between the upper mold and the lower mold, the lower end of the upper mold core penetrates through an inner hole of the upper mold to be attached to the middle mold core, and the upper end of the lower mold core penetrates through an inner hole of the lower mold to be connected with the middle mold core. The problems of mold positioning surface scratching, mold pressing damage, product chipping, surface pocking marks and the like are solved. The device is high in processing efficiency, good in precision control and stable and reliable in quality, and can meet the processing requirements of high precision and good appearance of phenolic plastic spherical handles in batch production.

Description

Technical Field

[0001] The invention relates to the technical field of non-metallic material molding for aviation, and in particular to a phenolic plastic ball handle mold structure and a molding method. Background Art

[0002] A ball handle is a matching product for a certain type of aircraft landing gear control switch, mainly used to adjust the switch position. The inner hole slot size of the ball handle is 2.6+0.12 0, which is mainly used to assemble the handle rod. For plastic pressed products, the dimensional accuracy requirement is relatively high; the spherical outer surface and the straight grain part are mainly used for handholding, which require good appearance and smooth feel. Due to the high inner hole size requirement and relatively complex appearance, its molding process is relatively difficult.

[0003] The handle is made of phenolic plastic, which has good heat resistance and electrical insulation, is hard and wear-resistant, has good dimensional stability, and can withstand most chemicals. It is mainly formed by compression molding, transfer molding and injection molding. When compression molding is used, the pressure per unit area of ​​the mold is about 30MPa. Since the handle is spherical and there is a circle of straight knurling in the middle, there are problems such as scratches on the mold positioning surface, mold crushing, product falling off, and surface pitting during processing. Summary of the invention

[0004] Purpose of the present invention:

[0005] A phenolic plastic ball handle mold structure and a molding method are proposed, which have high processing efficiency, good precision control, stable and reliable quality and can meet the needs of mass production.

[0006] Technical solution:

[0007] A phenolic plastic ball handle mold structure comprises an upper core 1, an upper mold 2, a sleeve 3, a middle core 4, a middle mold plate 5, a lower mold 6 and a lower core 7. The upper mold 2 and the lower mold 6 are respectively arranged at the upper and lower parts of the sleeve 3, and the middle mold plate 5 is arranged between the upper mold 2 and the lower mold 6. The lower end of the upper core 1 passes through the inner hole of the upper mold 2 and fits with the middle core 4, and the upper end of the lower core 7 passes through the inner hole of the lower mold 6 and is connected to the middle core 4.

[0008] Furthermore, both ends of the upper and lower inner walls of the sleeve 3 are provided with outwardly extending conical surfaces, the length of the conical surfaces is 20 mm, and the taper is 3°.

[0009] Furthermore, the middle template 5 is a circular ring structure, and the edge of its inner hole is provided with straight knurling.

[0010] Furthermore, the upper mold 2 is a cylindrical structure with an arc surface at the bottom, and the lower mold 6 is a cylindrical structure with an arc surface at the top. The arc surface at the bottom of the upper mold 2, the arc surface at the top of the lower mold 6 and the knurled surface of the middle mold 5 form a cavity.

[0011] Furthermore, the largest outer cylindrical surface of the upper mold 2 is evenly provided with 8 material running grooves along the axial direction; the width of the material running groove is 4 mm, the depth is 2 mm, and the material running groove is a rectangular groove, which is easier to clean excess material.

[0012] Furthermore, two symmetrically distributed mold opening grooves with a depth of 5 mm and a width of 6 mm are arranged at the bottom of the largest outer cylindrical surface of the upper mold 2 .

[0013] Furthermore, two symmetrically distributed mold opening grooves with a depth of 5 mm and a width of 6 mm are arranged on the outer cylindrical surface of the lower mold 6 .

[0014] Furthermore, the upper core 1, the upper die 2, the sleeve 3, the middle core 4, the middle die plate 5, the lower die 6 and the lower core 7 are all made of alloy tool steel Cr12MoV material.

[0015] Furthermore, the outer circle of the lower die 6 is symmetrically milled and flattened at two locations, with a milling depth of 6 mm, and an error-proof inspection through hole is formed between the flattened plane and the inner wall of the sleeve 3 .

[0016] The method for molding a phenolic plastic ball handle using the mold structure comprises the following steps:

[0017] a. Weigh the phenolic plastic raw materials using an electronic balance according to the process requirements;

[0018] b. Preheat the mold structure to the specified temperature, which is 170℃±3℃;

[0019] c. Install the middle core 4 on the lower core 7, the middle core 4 and the lower core 7 are interference fit, and after the combination of the lower core 7 and the middle core 4 is installed into the inner hole of the lower mold 6, the whole is installed into the bottom of the inner hole of the sleeve 3; then, the middle template 5 is installed into the sleeve 3 and contacts with the lower mold 6, and the weighed phenolic plastic raw material is poured into the cavity formed by the middle template 5 and the lower mold 6 at one time. The mold shall not be shaken, so that the raw material presents a small hill shape; finally, the upper core 1 is installed into the inner hole of the upper mold 2 and the upper part of the inner hole of the sleeve 3, so that the upper mold 2 contacts the upper surface of the middle template 5, and the middle core 4 fits with the upper core 1, and the mold is placed in a press for curing;

[0020] d. According to the process requirements, after keeping the temperature at 170℃±3℃ for 10min±1min, remove the mold from the press, take out the upper mold 2 equipped with the upper core 1, the lower mold 6 equipped with the lower core 7 and the middle core, and the middle mold plate 5 from the sleeve, open the upper mold 2 and the lower mold 6, and finally remove the cured ball handle from the middle mold plate 5;

[0021] e. Remove the burrs on the parting surface of the ball handle;

[0022] f. Inspect the size and appearance of the ball handle according to the process requirements.

[0023] Beneficial effects:

[0024] The present invention provides a phenolic plastic ball handle mold structure and molding method, and solves the problems of mold positioning surface scratches, mold crushing, product falling, surface pitting, etc. through a sleeve, an upper mold and a lower mold positioning structure of the phenolic plastic compression molding mold and a molding process method. The present invention has high processing efficiency, good precision control, stable and reliable quality, and can meet the high-precision and good-appearance processing requirements of mass production of phenolic plastic ball handles. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. It is obvious that the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic structural diagram of a phenolic plastic ball handle mold of the present invention;

[0027] Among them, 1, upper core, 2, upper die, 3, sleeve, 4, middle core, 5, middle die plate, 6, lower die, 7, lower core;

[0028] Figure 2 It is a schematic diagram of the upper core structure of the present invention;

[0029] Figure 3 is a top view of the upper core structure of the present invention;

[0030] Figure 4 It is a schematic diagram of the upper mold structure of the present invention;

[0031] Figure 5 is a top view of the upper mold structure of the present invention;

[0032] Figure 6 It is a schematic diagram of the sleeve structure of the present invention;

[0033] Figure 7 is a top view of the sleeve structure of the present invention;

[0034] Figure 8 It is a schematic diagram of the core structure of the present invention;

[0035] Fig. 9 It is a schematic diagram of the template structure in the present invention;

[0036] Fig.10 It is a top view of the template structure in the present invention;

[0037] Fig.11 It is a partial enlarged schematic diagram of the template in the present invention;

[0038] Fig.12 It is a schematic diagram of the lower mold structure of the present invention;

[0039] Fig.13 It is a side view of the lower mold structure of the present invention;

[0040] Fig.14 It is a top view of the lower mold structure of the present invention;

[0041] Fig.15 is a side view of the lower core structure of the present invention;

[0042] Fig.16 It is a top view of the lower core of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] like Figure 1As shown, the present invention proposes a phenolic plastic ball handle mold structure, including an upper core 1, an upper mold 2, a sleeve 3, a middle core 4, a middle template 5, a lower mold 6 and a lower core 7. The upper mold 2 and the lower mold 6 are respectively arranged at the upper and lower parts of the sleeve 3, and the middle template 5 is arranged between the upper mold 2 and the lower mold 6. The lower end of the upper core 1 passes through the inner hole of the upper mold 2 to fit with the middle core 4, and the upper end of the lower core 7 passes through the inner hole of the lower mold 6 to connect with the middle core 4. The present invention innovatively designs a phenolic plastic compression molding mold and a molding process method of the sleeve 3, the upper and lower molds 6 positioning structure, which solves the problems of scratches on the mold positioning surface, mold crushing, product falling off, surface pitting, etc.

[0047] The mold structure of the present invention as a whole adopts the positioning structure of the sleeve 3, the upper and lower molds 6, and eliminates positioning structures such as positioning pins and positioning rings, thereby achieving the effect of simple mold structure and convenient operation.

[0048] In the present invention, the ends of the upper and lower inner walls of the sleeve 3 are provided with outwardly extending conical surfaces, the length of the conical surfaces is 20 mm, and the taper is 3°. The positioning length of the upper and lower molds 6 and the length of the sleeve is shortened, and the demoulding difficulty is reduced while ensuring reliable positioning, and the positioning surfaces of the sleeve 3 and the upper and lower molds 6 can be effectively prevented from being scratched.

[0049] In the present invention, the middle template 5 is a circular ring structure, and the edge of its inner hole is provided with straight knurling. It is used for direct molding of straight knurling to avoid the phenomenon of block falling at the knurling caused by mechanical processing of straight knurling. In addition, a single set of molding mold is equipped with two interchangeable middle templates 5, which are used alternately during molding to achieve the purpose of cold start molding, so as to prevent the phenomenon of block falling at the straight knurling during hot start molding.

[0050] Among them, the upper mold 2 is a cylindrical structure with an arc-shaped surface at the bottom, and the lower mold 6 is a cylindrical structure with an arc-shaped surface at the top. The arc-shaped surface at the bottom of the upper mold 2, the arc-shaped surface at the top of the lower mold 6 and the knurled surface of the middle mold 5 form a cavity for placing phenolic plastic raw materials for molding. When adding materials, all the required materials are poured into the cavity at one time to avoid shaking. The molds are directly closed and pressed to avoid the pitting phenomenon on the surface of the spherical handle caused by a large amount of material extrusion.

[0051] In the present invention, 8 material running grooves along the axial direction are evenly arranged on the largest outer cylindrical surface of the upper mold 2; the width of the material running groove is 4 mm, the depth is 2 mm, and the material running groove is a rectangular groove, which has enough space to accommodate excess material and is easier to clean up the excess material.

[0052] In the present invention, two symmetrically distributed mold opening grooves with a depth of 5 mm and a width of 6 mm are arranged at the bottom of the largest outer cylindrical surface of the upper mold 2. Two symmetrically distributed mold opening grooves with a depth of 5 mm and a width of 6 mm are arranged on the outer cylindrical surface of the lower mold 6. Two symmetrical mold opening grooves with a height of 5 and a width of 6 are opened on the upper and lower molds to ensure uniform demoulding force and avoid the phenomenon of parts falling off caused by knocking the mold and uneven force during mold opening.

[0053] Generally speaking, the mold materials used for plastic compression molds are T7A and T8A, and the heat treatment hardness is required to be HRC50-55. This kind of steel can obtain high hardness and good wear resistance after heat treatment, but the disadvantage is that the hardenability is poor and it is easy to deform and crack during heat treatment. In order to solve this problem, after screening and analyzing different mold steels, it is finally determined that the upper core 1, upper mold 2, sleeve 3, middle core 4, middle mold plate 5, lower mold 6 and lower core 7 are all made of alloy tool steel Cr12MoV material, and the forging requirements are increased to make the material particle size finer, the edges and corners rounded, and the plasticity and toughness of the workpiece are improved to avoid fracture during the use of the mold. The hardness after heat treatment is HRC55-60. This material has high hardness, wear resistance and toughness, especially better hardenability, hardenability and hot hardness. In addition, it is required to forge the material to make the material particle size finer, the edges and corners rounded, the plasticity and toughness of the workpiece are improved, and the fracture during the use of the mold is avoided.

[0054] In the present invention, the outer circle of the lower die 6 is symmetrically milled at two places, the milling depth is 6mm, and an error-proof inspection through hole is formed between the flattened plane and the inner wall of the sleeve 3. While ensuring effective positioning, the phenomenon of missing the middle template can be effectively avoided. When the middle template is missed, the material will leak directly from the lower die through hole after adding the material, and the missing middle template can be found visually.

[0055] The method for molding a phenolic plastic ball handle using the mold structure comprises the following steps:

[0056] a. Weigh the phenolic plastic raw materials using an electronic balance according to the process requirements;

[0057] b. Preheat the mold structure to the specified temperature, which is 170℃±3℃;

[0058] c. Install the middle core 4 on the lower core 7, the middle core 4 and the lower core 7 are interference fit, and after the combination of the lower core 7 and the middle core 4 is installed into the inner hole of the lower mold 6, the whole is installed into the bottom of the inner hole of the sleeve 3; then, the middle template 5 is installed into the sleeve 3 and contacts with the lower mold 6, and the weighed phenolic plastic raw material is poured into the cavity formed by the middle template 5 and the lower mold 6 at one time. The mold shall not be shaken, so that the raw material presents a small hill shape; finally, the upper core 1 is installed into the inner hole of the upper mold 2 and the upper part of the inner hole of the sleeve 3, so that the upper mold 2 contacts the upper surface of the middle template 5, and the middle core 4 fits with the upper core 1, and the mold is placed in a press for curing;

[0059] d. According to the process requirements, after keeping the temperature at 170℃±3℃ for 10min±1min, remove the mold from the press, take out the upper mold 2 equipped with the upper core 1, the lower mold 6 equipped with the lower core 7 and the middle core, and the middle mold plate 5 from the sleeve, open the upper mold 2 and the lower mold 6, and finally remove the cured ball handle from the middle mold plate 5;

[0060] e. Remove the burrs on the parting surface of the ball handle;

[0061] f. Inspect the size and appearance of the ball handle according to the process requirements.

[0062] In the molding method of the present invention, since phenolic plastic is brittle at a high temperature after mold opening, the knurling part is particularly prone to falling off when the part is directly removed after mold opening. Therefore, a single set of molding molds is equipped with two interchangeable middle mold plates 5, which are used alternately during molding to achieve the purpose of cold mold opening, so as to prevent the straight knurling part from falling off during hot mold opening.

[0063] In view of the phenomenon that the center template 5 was missed many times during the production process of the original mold, the mold was improved and the error prevention function was added. Two through holes were symmetrically milled on the outer circle of the lower mold 6, which can effectively avoid the phenomenon of missing the center template while ensuring effective positioning. When the center template 5 is missed, the material will leak directly from the through holes of the lower mold 6 after adding the material, and the missing center template 5 can be found visually.

[0064] Since the handle is spherical, it is impossible to design a feeding cavity, so the mold structure is designed as an open mold. After repeated verification, the feeding method is solidified. When feeding, all the required materials are poured into the cavity at one time to avoid shaking, and the mold is directly closed to press, which can avoid the pitting phenomenon on the surface of the spherical handle caused by a large amount of material extrusion.

[0065] Embodiment 1 of the present invention:

[0066] A ball handle is required to have a diameter of φ30, a height of 28, a straight knurling diameter of φ32, a designed mold outer diameter of φ83, a height of 82, a mold positioning dimension of φ55H7 / f6, 8 running grooves of 4 width and 2 depth, and 2 symmetrical mold opening grooves of 5 height and 6 width. During molding, the weight of the material added is 20g.

[0067] Example 2: The diameter of the ball handle B is φ35, the height is 33, the straight knurling diameter is φ37, the outer diameter of the designed mold is φ88, the height is 87, the mold positioning size is φ60H7 / f6, 8 running grooves with a width of 4 and a depth of 2 are set, and 2 symmetrical mold opening grooves with a height of 5 and a width of 6 are set. During molding, the weight of the material added is 35g.

[0068] Example 3: The diameter of the C ball handle is φ50 and the height is 48. The handle has no straight knurling. The outer diameter of the mold is designed to be φ110 and the height is 105. The mold positioning size is φ76H7 / f6. 8 running grooves with a width of 4 and a depth of 3 are set, and 2 symmetrical mold opening grooves with a height of 6 and a width of 6 are set. During molding, the weight of the material added is 90g:

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A phenolic plastic ball handle mold structure, characterized in that: It includes an upper core, an upper mold, a sleeve, a middle core, a middle mold plate, a lower mold and a lower core. The upper mold and the lower mold are respectively arranged at the upper and lower parts of the sleeve, the middle mold plate is arranged between the upper mold and the lower mold, the lower end of the upper core passes through the inner hole of the upper mold to fit the middle core, and the upper end of the lower core passes through the inner hole of the lower mold to be connected to the middle core.

2. The phenolic plastic ball handle mold structure according to claim 1, characterized in that: Conical surfaces extending outward are arranged at both ends of the upper and lower inner walls of the sleeve, the length of the conical surfaces is 20 mm, and the taper is 3°.

3. The phenolic plastic ball handle mold structure according to claim 1, characterized in that: The middle template is a circular ring structure, and the edge of its inner hole is provided with straight knurling.

4. The phenolic plastic ball handle mold structure according to claim 3, characterized in that: The upper die is a cylindrical structure with an arc surface at the bottom, and the lower die is a cylindrical structure with an arc surface at the top. The arc surface at the bottom of the upper die, the arc surface at the top of the lower die and the knurled surface of the middle die form a cavity.

5. The phenolic plastic ball handle mold structure according to claim 4, characterized in that: The largest outer cylindrical surface of the upper die is evenly provided with 8 material running grooves along the axial direction; the width of the material running groove is 4mm, the depth is 2mm, and the material running groove is a rectangular groove, which is easier to clean excess material.

6. The phenolic plastic ball handle mold structure according to claim 5, characterized in that: The bottom of the largest outer cylindrical surface of the upper mold is provided with two symmetrically distributed mold opening grooves with a depth of 5 mm and a width of 6 mm.

7. The phenolic plastic ball handle mold structure according to claim 5, characterized in that: Two symmetrically distributed mold opening grooves with a depth of 5 mm and a width of 6 mm are set on the outer cylindrical surface of the lower mold.

8. The phenolic plastic ball handle mold structure according to claim 1, characterized in that: The upper core, the upper die, the sleeve, the middle core, the middle template, the lower die and the lower core are all made of alloy tool steel Cr12MoV material.

9. The phenolic plastic ball handle mold structure according to claim 1, characterized in that: The outer circle of the lower die is symmetrically milled at two locations, with a milling depth of 6mm, and an error-proof inspection through hole is formed between the flattened plane and the inner wall of the sleeve.

10. A method for molding a phenolic plastic ball handle using the mold structure as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: a. Weigh the phenolic plastic raw materials using an electronic balance according to the process requirements; b. Preheat the mold structure to the specified temperature, which is 170℃±3℃; c. Install the middle core on the lower core, the middle core and the lower core are interference fit, and after the combination of the lower core and the middle core is installed into the inner hole of the lower mold, the whole is installed into the bottom of the inner hole of the sleeve; then install the middle template into the sleeve and make it contact with the lower mold, and pour the weighed phenolic plastic raw materials into the cavity formed by the middle template and the lower mold at one time. The mold must not be shaken, so that the raw materials appear in the shape of a small hill; finally, install the upper core into the inner hole of the upper mold and into the upper part of the inner hole of the sleeve, so that the upper mold contacts the upper surface of the middle template, and the middle core fits the upper core, and the mold is placed in a press for curing; d. According to the process requirements, after keeping the temperature at 170℃±3℃ for 10min±1min, remove the mold from the press, take out the upper mold with the upper core, the lower mold with the lower core and the middle core, and the middle mold plate from the sleeve, open the upper mold and the lower mold, and finally remove the cured ball handle from the middle mold plate; e. Remove the burrs on the parting surface of the ball handle; f. Inspect the size and appearance of the ball handle according to the process requirements.

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