CN117944227A

CN117944227A - Cab top cover injection mold and injection molding top cover assembly thereof

Info

Publication number: CN117944227A
Application number: CN202410142030.XA
Authority: CN
Inventors: 朱永彬; 王洪峰; 王丙港; 谭大永; 管春乐
Original assignee: Weifang Chuanjiang Plastic Products Co ltd
Current assignee: Weifang Chuanjiang Plastic Products Co ltd
Priority date: 2024-02-01
Filing date: 2024-02-01
Publication date: 2024-04-30

Abstract

The invention relates to the technical field of injection molding of cab top cover assemblies, in particular to a cab top cover injection mold and an injection molded top cover assembly thereof. The top cover assembly is firm in external connection, not easy to crack and good in sealing effect, the added locking buckles and positioning bayonet ribs have significance in reducing wind resistance noise and not easy to crack in firmness, and the top cover assembly realizes efficient and rapid injection molding and demolding processing through the cab top cover injection mold.

Description

Cab top cover injection mold and injection molding top cover assembly thereof

Technical Field

The invention relates to the technical field of injection molding of cab top cover assemblies, in particular to a cab top cover injection mold and an injection molded top cover assembly thereof.

Background

The cab roof is a part of the body structure and is generally referred to as a cover over the cab. It provides sunshade, rainproof and sound insulation functions for drivers and passengers, and simultaneously protects the safety of equipment and passengers in the vehicle. The cab roof is an indispensable part of the vehicle body structure, and has important significance for ensuring the safety performance and the use comfort of the vehicle.

The existing cab roof has poor tightness, namely the problems of cracking and tightness of the cab roof can cause noise and vibration to increase, the comfort level of personnel such as a driver can be influenced, and the driving performance of a vehicle can be negatively influenced.

In addition, the bottom end of a valve needle hot runner in the existing processing injection mold is of a conventional conical structure, proper cooling is realized only through the hot runner in the injection molding process, insufficient cooling can be caused, the later-stage product shrink, deformation or other defects can be caused, and in addition, the problems of insufficient product strength and the like can occur.

Disclosure of Invention

The invention provides a cab top cover injection mold and an injection molded top cover assembly thereof, which are used for solving the technical problems of poor installation and sealing and firmness of the existing injection molded cab top cover, poor corresponding mold effect and mismatching.

In order to solve the problems, the injection mold for the cab top cover and the injection molding top cover assembly thereof provided by the invention adopt the following technical scheme:

the cab top cover injection mold comprises a fixed mold assembly and a movable mold assembly matched with the fixed mold assembly, wherein an injection molding cavity of an injection molding product is formed after the fixed mold assembly and the movable mold assembly are assembled, and the fixed mold assembly comprises an A-type hot runner injection molding module and a B-type hot runner injection molding module;

the A-type hot runner injection molding module comprises a first hot runner, a first valve needle is arranged in the first hot runner, a first cylinder for driving the first valve needle to move up and down is arranged above the first hot runner, a first valve needle sleeve is arranged at the inner top end of the first hot runner, the first valve needle vertically penetrates through the first valve needle sleeve, a first pouring nozzle head is arranged at the bottom end of the first hot runner, and the upper side wall of the first pouring nozzle head is of a fold structure formed by a groove and a convex edge.

By adopting the technical scheme, the groove and the convex ridge are designed on the side wall of the upper section of the first pouring nozzle to form the fold structure, the auxiliary cooling effect of the melt is increased, the defects of shrinkage deformation and the like in the later period of products are reduced, in addition, the structure can improve the flowing and filling effects of the plastic melt, the turbulence effect of the plastic melt is increased, the turbulence degree of the melt is improved, and the melt is promoted to fill the die cavity better.

In addition, the flow balance in the hot runner system can be improved through the fold structure, and the appearance quality and the dimensional accuracy of the plastic product are improved.

The B-type hot runner injection molding module comprises a second hot runner, a second valve needle is arranged in the second hot runner, a second cylinder for driving the second valve needle to move up and down is arranged above the second hot runner, second valve needle sleeves are arranged at the upper end and the lower end in the second hot runner, a second pouring nozzle is arranged at the bottom end of the second hot runner, and the section of an inner hole at the lower end of the second pouring nozzle is in an upper trapezoid and a lower trapezoid.

By adopting the technical scheme, the direction and the speed of the plastic melt can be changed in the flowing process due to the particularity of the trapezoid cross section shape, so that the filling effect is improved. Particularly, when filling a long-flow or complex cavity, the plastic melt can be ensured to flow into all corners of the mold better, and the filling uniformity and integrity are improved.

The upper and lower opposite trapezoid cross sections can form two V-shaped channels, which is beneficial to air discharge. During injection molding, air needs to be rapidly exhausted to avoid problems such as cavitation and short shot. And the design can increase the air discharging channel, improve the air discharging efficiency, thereby reducing the risks of cavitation and short shot.

Furthermore, the trapezoid cross section can increase the contact area of the plastic melt, so that the cooling effect is increased in a certain degree in an auxiliary way, and the risks of deformation and cracking of the product are reduced.

The bottom of first needle and second needle all includes symmetrical short portion and long portion, the side of short portion and long portion all is equipped with the plain noodles.

Half through the needle bottom is long portion, the filling condition of adaptation mould that can be better improves the control accuracy of flow, makes the needle cut more easily in the course of working, operation such as grinding through the plane, improves machining efficiency and quality. Simultaneously, the plane section has also made things convenient for the installation of needle for the needle can be fixed more steadily.

Further, the cover half subassembly includes pouring plate and butt in the last shaping template of pouring plate below, be equipped with the pouring mouth of pipe on the pouring plate, be equipped with the pouring runner board with pouring mouth of pipe intercommunication in the pouring plate, first hot runner with one side of second hot runner all is equipped with the side mouth of pipe with pouring runner board intercommunication.

Further, the movable mould assembly comprises a lower forming template, an injection molding cavity of an injection molding product is formed after the upper forming template and the lower forming template are assembled, and cooling pipe assemblies are arranged in the upper forming template and the lower forming template.

Further, the cooling pipe assembly comprises a transverse pipe fitting which is transversely arranged and communicated with the outside, a vertical cooling pipe fitting is communicated with the transverse pipe fitting, and the vertical cooling pipe fitting on the transverse pipe fitting is a plurality of vertical cooling pipe fittings which are vertically arranged at intervals, and the diameter of the vertical cooling pipe fitting is larger than that of the transverse pipe fitting.

By adopting the technical scheme, the cooling pipe assemblies are densely and uniformly distributed to cover the whole injection cavity, so that the contact area of cooling water or coolant and the mold is increased, and heat conduction and dissipation are accelerated. The heat in the mould is taken away more quickly, the temperature of the mould is reduced, the injection molding period is accelerated, and the production efficiency is improved.

In addition, the temperature difference among all parts of the die can be reduced by uniform distribution. The problems of uneven shrinkage, warping, deformation and the like of the product caused by uneven temperature are reduced, and the stability of the size of the product is improved.

Further, a pushing mechanism is arranged below the lower molding template and comprises a pushing bottom plate which is abutted to the lower molding template, a thimble is arranged on the upper surface of the pushing bottom plate, the thimble points to the injection molding cavity, a top plate is abutted to the lower part of the pushing bottom plate, a lower fixing plate is fixedly arranged at the bottom end of the top plate, a guide pillar is arranged on the lower fixing plate, and the guide pillar penetrates through the top plate and the pushing bottom plate and stretches into the lower molding template;

the pushing bottom plate is provided with a pushing cylinder, and a driving rod of the pushing cylinder penetrates through the pushing bottom plate and is connected with the top plate.

Further, the pushing bottom plate is provided with a model component which enables the inner wall of the top cover body to form a locking buckle; the model subassembly is including being fixed in the stand of pushing away on the bottom plate, the top of stand is equipped with the locking and detains the shaping module, the stand is with the detachable plug bush cooperation of locking and detaining the shaping module, the bottom of stand is equipped with the fixed block, the fixed block is fixed in on the pushing away the bottom plate through the draw-in groove seat, the both sides of draw-in groove seat all are equipped with the guide way, be equipped with the guide bar of vertical run through the guide way on the roof.

By adopting the technical scheme, the locking buckle structure is formed through the model component, the locking buckle and the locking buckle forming module are in a back-off mode, the locking buckle forming module is detachable, interference to the demolding process is avoided, and the practicability is improved.

The cab top cover injection mold injection molding top cover assembly comprises a top cover body, wherein locking buckles and positioning bayonet ribs which are distributed in a staggered mode are circumferentially arranged on the inner surface of the side wall of the top cover body.

Further, the side view section of the locking buckle is wedge-shaped, and the included angle alpha between the bottom end surface and the upper end surface is 25-35 degrees.

Further, the upper end face of the positioning bayonet rib is provided with a positioning step.

Further, the inner surface of the top cover body is provided with a cross-shaped reinforcing convex rib.

By adopting the technical scheme, the top cover body is firm in connection with the outside, is not easy to crack and has good sealing effect, external noise and vibration are effectively isolated, a more comfortable working environment is provided for a driver, and the top cover of the cab has good sealing property, so that rainwater can be prevented from penetrating, internal equipment and circuits are protected, faults and damage caused by humidity are avoided, and the cost of later maintenance and repair is reduced.

The injection mold for the cab top cover and the injection molded top cover assembly thereof provided by the invention have the beneficial effects that: the injection mold has good injection uniformity and integrity, high injection efficiency, firm connection of the top cover assembly to the outside, difficult cracking and good sealing effect, the added locking buckle and positioning bayonet ribs have important significance for reducing wind resistance noise and difficult cracking, and the top cover assembly realizes high-efficiency and rapid injection molding and demolding processing through the cab top cover injection mold.

Drawings

The above, as well as additional purposes, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description when read in conjunction with the accompanying drawings. In the drawings, embodiments of the invention are illustrated by way of example and not by way of limitation, and like reference numerals refer to similar or corresponding parts and in which:

FIG. 1 is a front view of an injection mold for a cab roof of the present invention;

FIG. 2 is a cross-sectional view of the cab roof injection mold of the present invention;

FIG. 3 is an enlarged view of a portion of area A of FIG. 2;

FIG. 4 is an enlarged view of a portion of region B of FIG. 2;

FIG. 5 is a schematic diagram of an A-type hot runner injection molding module according to the present invention;

FIG. 6 is an enlarged view of a portion of region C of FIG. 5;

FIG. 7 is a schematic diagram of a B-type hot runner injection molding module according to the present invention;

FIG. 8 is a schematic view of the first valve needle of the present invention;

FIG. 9 is a schematic diagram of the structure of the region D in FIG. 8;

FIG. 10 is a schematic view of a portion of the injection mold for a cab roof of the present invention;

FIG. 11 is a schematic view of a modular assembly of the present invention;

FIG. 12 is a partial cross-sectional view of the injection mold for the cab roof of the present invention;

FIG. 13 is a schematic view of the structure of the top cover body according to the present invention;

Fig. 14 is a partial enlarged view of a region H in fig. 13.

Reference numerals illustrate:

11. An A-type hot runner injection molding module; 111. a first hot runner; 112. a first valve needle; 1121. a short section; 1122. a long portion; 1123. cutting the dough flat; 113. a first cylinder; 114. a first pouring nozzle head; 115. a pleated structure; 116. a first needle sleeve; 117. a side pipe orifice; 12. a B-type hot runner injection molding module; 121. a second hot runner; 122. a second valve needle; 123. a second needle sleeve; 124. a second pouring nozzle; 125. a second cylinder; 13. casting plate; 131. pouring pipe orifice; 132. pouring a runner plate; 14. an upper molding template; 2. a movable mold assembly; 21. a lower molding template; 22. pushing the bottom plate; 23. a thimble; 24. a top plate; 25. a lower fixing plate; 251. a guide post; 26. pushing cylinder; 27. a model component; 271. a column; 272. locking the buckle forming module; 273. a fixed block; 274. a clamping groove seat; 275. a guide through hole; 276. a guide rod; 3. a cooling tube assembly; 31. a transverse tube; 32. vertical cooling pipe fittings; 4. a top cover body; 41. locking the buckle; 42. positioning bayonet ribs; 421. positioning the step; 43. cross-shaped reinforcing ribs.

Detailed Description

The following description of the embodiments of the present invention will be made more complete and clear to those skilled in the art by reference to the figures of the embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Any number of elements in the figures are for illustration and not limitation, and any naming is used for distinction only and not for any limiting sense.

The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments thereof.

Example 1 of cab roof injection mold provided by the invention:

as shown in figures 1 to 14 of the drawings,

The injection molding device comprises a fixed die assembly and a movable die assembly 2 matched with the fixed die assembly, wherein an injection molding cavity of an injection molding product is formed after the fixed die assembly and the movable die assembly 2 are clamped, and the fixed die assembly comprises an A-type hot runner injection molding module 11 and a B-type hot runner injection molding module 12.

In this embodiment, as shown in fig. 5 and 6, the a-type hot runner injection molding module 11 includes a first hot runner 111, a first valve needle 112 is disposed in the first hot runner 111, a first cylinder 113 that drives the first valve needle 112 to move up and down is disposed above the first hot runner 111, a first valve needle sleeve 116 is disposed at the top end in the first hot runner 111, the first valve needle 112 vertically penetrates through the first valve needle sleeve 116, a first pouring nozzle 114 is disposed at the bottom end of the first hot runner 111, and a fold structure 115 formed by a groove and a convex edge is disposed on the upper side wall of the first pouring nozzle 114.

Wherein, through all design have fold structure 115 that recess and flange formed at the upper segment lateral wall of first pouring nozzle 114, i.e. inner wall surface and outer wall surface, increase the supplementary cooling effect of fuse-element, reduce defects such as shrinkage deformation that appear in the later stage of product, in addition, can realize improving the flow and the effect of filling of plastics fuse-element through this structure, increase the vortex effect of plastics fuse-element, improve the turbulent flow degree of fuse-element to promote the fuse-element to fill the mould die cavity better.

In addition, flow balance in the hot runner system may be improved by the pleated structure 115, reducing the risk of cavitation and shortshot. In addition, the design can also improve the appearance quality and the dimensional accuracy of the plastic product.

In this embodiment, as shown in fig. 7, the B-type hot runner injection molding module 12 includes a second hot runner 121, a second valve needle 122 is disposed in the second hot runner 121, a second cylinder 125 for driving the second valve needle 122 to move up and down is disposed above the second hot runner 121, second valve needle sleeves 123 are disposed at the upper and lower ends of the second hot runner 121, a second pouring nozzle 124 is disposed at the bottom end of the second hot runner 121, and the inner hole section at the lower end of the second pouring nozzle 124 is in an upper trapezoid and a lower trapezoid.

Wherein, due to the particularity of the trapezoid cross-section shape, the direction and the speed of the plastic melt can be changed in the flowing process, thereby improving the filling effect. Particularly, when filling a long-flow or complex cavity, the plastic melt can be ensured to flow into all corners of the mold better, and the filling uniformity and integrity are improved.

The fixed die assembly comprises a pouring plate 13 and an upper molding template 14 which is abutted to the lower side of the pouring plate 13, a pouring pipe orifice 131 is arranged on the pouring plate 13, a pouring runner plate 132 communicated with the pouring pipe orifice 131 is arranged in the pouring plate 13, and side pipe orifices 117 communicated with the pouring runner plate 132 are arranged on one sides of the first hot runner 111 and the second hot runner 121.

In this embodiment, as shown in fig. 8 and 9, the bottom ends of the first valve needle 112 and the second valve needle 122 each include a short portion 1121 and a long portion 1122 that are symmetrical, and the side surfaces of the short portion 1121 and the long portion 1122 are each provided with a flat cut surface 1123.

The half bottom of the valve needle is the long part 1122, so that the valve needle can be better adapted to the filling condition of a die, the flow control precision is improved, the valve needle is easier to cut, grind and the like in the processing process through the plane 1123, and the processing efficiency and quality are improved. At the same time, the flat cut surface 1123 also facilitates the installation of the valve needle so that the valve needle can be more stably fixed.

In this embodiment, the movable mold assembly 2 includes a lower molding mold plate 21, an injection molding cavity of an injection molding product is formed after the upper molding mold plate 14 and the lower molding mold plate 21 are assembled, and cooling tube assemblies 3 are respectively disposed in the upper molding mold plate 14 and the lower molding mold plate 21.

In this embodiment, the cooling pipe assembly 3 includes a transverse pipe fitting 31 that transversely sets up and externally communicates, the intercommunication is equipped with vertical cooling pipe fitting 32 on the transverse pipe fitting 31, vertical cooling pipe fitting 32 on the transverse pipe fitting 31 is a plurality of and the diameter of vertical cooling pipe fitting 32 of interval vertical arrangement is greater than the diameter of transverse pipe fitting 31.

Wherein, the cooling pipe assembly 3 is densely and evenly distributed to cover the whole injection cavity, and increases the contact area of cooling water or coolant and the mold, thereby accelerating heat conduction and dissipation. The heat in the mould is taken away more quickly, the temperature of the mould is reduced, the injection molding period is accelerated, and the production efficiency is improved.

In this embodiment, a pushing mechanism is disposed below the lower molding template 21, the pushing mechanism includes a pushing bottom plate 22 that is abutted to the lower molding template 21, a thimble 23 is disposed on the upper surface of the pushing bottom plate 22, the thimble 23 points to the injection molding cavity, a top plate 24 is abutted to the lower portion of the pushing bottom plate 22, a lower fixing plate 25 is fixedly disposed at the bottom end of the top plate 24, and a guide pillar 251 is disposed on the lower fixing plate 25, and the guide pillar 251 penetrates through the top plate 24 and the pushing bottom plate 22 and extends into the lower molding template 21;

The pushing bottom plate 22 is provided with a pushing cylinder 26, and a driving rod of the pushing cylinder 26 penetrates through the pushing bottom plate 22 and is connected with the top plate 24.

When demolding is needed, the driving rod of the pushing cylinder 26 acts and pushes the pushing cylinder downwards, the top plate 24 is not moved, the pushing bottom plate 22 moves upwards at the moment, the pushing bottom plate 22 drives the ejector pins 23 to move upwards at the same time of moving upwards, the ejection of a product is realized, and the stability of the pushing process is improved through the guide posts 251.

In this embodiment, the pushing bottom plate 22 is provided with a model component 27 for forming a locking buckle 41 on the inner wall of the top cover body 4, the model component 27 comprises a stand column 271 fixed on the pushing bottom plate 22, the top end of the stand column 271 is provided with a locking buckle forming module 272, the stand column 271 and the locking buckle forming module 272 are detachably matched in a plug bush, the bottom end of the stand column 271 is provided with a fixing block 273, the fixing block 273 is fixed on the pushing bottom plate 22 through a clamping groove seat 274, the fixing block 273 is clamped and fixed on the clamping groove seat 274, the clamping groove seat 274 is fixed on the pushing bottom plate 22, both sides of the clamping groove seat 274 are respectively provided with a guide through hole 275, and the top plate 24 is provided with a guide rod 276 vertically penetrating through the guide through hole 275.

The locking buckle 41 structure is formed through the model assembly 27, the locking buckle 41 and the locking buckle forming module 272 are in a reverse buckle mode, the locking buckle forming module 272 is detachable, interference to a demolding process is avoided, and the practicability is improved.

Specifically, when demolding is performed, the pushing bottom plate 22 moves upwards, and drives the upright post 271 to move upwards along with the top cover body 4, the locking buckle 41 and the locking buckle forming module 272 are inverted, and if the locking buckle forming module 272 does not move synchronously, the top cover body 4 can be interfered to be ejected upwards.

The utility model provides a driver's cabin top cap injection mold injection molding's top cap assembly, the lateral wall internal surface circumference of top cap body 4 is equipped with crisscross locking knot 41 and location bayonet rib 42 that distributes.

Wherein, the side view section of the locking buckle 41 is wedge-shaped, and the included angle alpha between the bottom end surface and the upper end surface is 27 degrees.

Wherein, the upper end surface of the positioning bayonet rib 42 is formed with a positioning step 421.

Wherein, the inner surface of the top cover body 4 is provided with a cross-shaped reinforcing rib 43.

The top cover body 4 is firm in external connection, difficult to fracture and sealed effectual, effectively keeps apart external noise and vibration, provides more comfortable operational environment for the driver, and the cab top cover leakproofness is good, can prevent rainwater infiltration, protects internal equipment and circuit, avoids trouble and the damage that produces because of the humidity, reduces the cost of later maintenance, maintenance.

From the foregoing description of the present specification, it will be further understood by those skilled in the art that terms such as "upper", "lower", "front", "rear", "left", "right", "width", "horizontal", "top", "bottom", "inner", "outer", and the like, which indicate an azimuth or a positional relationship, are based on the azimuth or the positional relationship shown in the drawings of the present specification, are for convenience only in explaining aspects of the present invention and simplifying the description, and do not explicitly or implicitly refer to devices or elements having to have the specific azimuth, be constructed and operate in the specific azimuth, and thus the azimuth or positional relationship terms described above should not be interpreted or construed as limitations of aspects of the present invention.

In addition, in the description of the present specification, the meaning of "plurality" means at least two, for example, two, three or more, etc., unless specifically defined otherwise.

Claims

1. The cab top cover injection mold comprises a fixed mold assembly and a movable mold assembly matched with the fixed mold assembly, wherein an injection molding cavity of an injection molding product is formed after the fixed mold assembly and the movable mold assembly are assembled;

The A-type hot runner injection molding module comprises a first hot runner, a first valve needle is arranged in the first hot runner, a first cylinder for driving the first valve needle to move up and down is arranged above the first hot runner, a first valve needle sleeve is arranged at the inner top end of the first hot runner, the first valve needle vertically penetrates through the first valve needle sleeve, a first pouring nozzle head is arranged at the bottom end of the first hot runner, and the side wall of the upper section of the first pouring nozzle head is of a fold structure formed by a groove and a convex edge;

The B-type hot runner injection molding module comprises a second hot runner, a second valve needle is arranged in the second hot runner, a second cylinder for driving the second valve needle to move up and down is arranged above the second hot runner, second valve needle sleeves are arranged at the upper end and the lower end in the second hot runner, a second pouring nozzle is arranged at the bottom end of the second hot runner, and the section of an inner hole at the lower end of the second pouring nozzle is in an upper trapezoid and a lower trapezoid;

2. The injection mold of the cab roof of claim 1, wherein the fixed mold assembly comprises a pouring plate and an upper molding template which is abutted to the lower part of the pouring plate, a pouring pipe orifice is arranged on the pouring plate, a pouring runner plate communicated with the pouring pipe orifice is arranged in the pouring plate, and side pipe orifices communicated with the pouring runner plate are arranged on one sides of the first hot runner and the second hot runner.

3. The cab roof injection mold of claim 2, wherein the movable mold assembly comprises a lower molding die plate, an injection molding cavity of an injection molding product is formed after the upper molding die plate and the lower molding die plate are clamped, and cooling pipe assemblies are arranged in the upper molding die plate and the lower molding die plate.

4. The injection mold of the cab roof according to claim 3, wherein the cooling pipe assembly comprises a transverse pipe fitting which is transversely arranged and communicated with the outside, vertical cooling pipe fittings are communicated with the transverse pipe fitting, the vertical cooling pipe fittings on the transverse pipe fitting are a plurality of vertical cooling pipe fittings which are vertically arranged at intervals, and the diameter of the vertical cooling pipe fittings is larger than that of the transverse pipe fittings.

5. The injection mold for the cab roof according to claim 3, wherein a pushing mechanism is arranged below the lower molding template, the pushing mechanism comprises a pushing bottom plate which is abutted to the lower molding template, a thimble is arranged on the upper surface of the pushing bottom plate, the thimble points to the injection mold cavity, a top plate is abutted to the lower side of the pushing bottom plate, a lower fixing plate is fixedly arranged at the bottom end of the top plate, and a guide pillar is arranged on the lower fixing plate, penetrates through the top plate and the pushing bottom plate and stretches into the lower molding template;

6. The injection mold of the cab roof according to claim 5, wherein the pushing bottom plate is provided with a mold assembly for forming a locking buckle on the inner wall of the roof body;

The model subassembly is including being fixed in the stand of pushing away on the bottom plate, the top of stand is equipped with the locking and detains the shaping module, the stand is with the detachable plug bush cooperation of locking and detaining the shaping module, the bottom of stand is equipped with the fixed block, the fixed block is fixed in on the pushing away the bottom plate through the draw-in groove seat, the both sides of draw-in groove seat all are equipped with the guide way, be equipped with the guide bar of vertical run through the guide way on the roof.

7. The top cover assembly formed by injection molding of the cab top cover injection mold is characterized in that the top cover assembly formed by injection molding of the cab top cover injection mold is formed by injection molding of the cab top cover injection mold according to any one of claims 1-6, and comprises a top cover body, wherein locking buckles and positioning bayonet ribs which are distributed in a staggered manner are circumferentially arranged on the inner surface of the side wall of the top cover body.

8. The cab roof injection mold injection molded roof assembly of claim 7 wherein the lock catch has a wedge-shaped side view cross section and an included angle α between the bottom end surface and the upper end surface of 25 ° -35 °.

9. The cab roof injection mold injection molded roof assembly of claim 7, wherein the upper end surface of the locating bayonet rib is formed with a locating step.

10. The cab roof injection mold injection molded roof assembly of claim 7, wherein the inner surface of the roof body is provided with cross-shaped reinforcing ribs.