CN117549470A - Rotational molding die for oil tank production - Google Patents

Abstract

The application relates to a rotational molding die for oil tank production, which relates to the technical field of rotational molding production, and comprises an upper die and a lower die, wherein the upper die and the lower die are detachably connected to form a cavity, the upper die comprises a first die plate and a second die plate which are mutually connected, and an adjusting cavity is formed between the second die plate and the second die plate; the lower die is rotationally connected with a partition plate for partitioning the cavity, a first forming sleeve and a second forming sleeve for forming the oil injection cylinder are arranged in the adjusting cavity, and the first forming sleeve slides relative to the second forming sleeve and pushes the partition plate to be abutted with the inner wall of the lower die. Be provided with the partition panel in this application, the cavity can be separated or not separated to the partition panel, and the oil tank of the different specification sizes of shaping has the effect of producing multiple oil tank, and the product class of production is richer.

Description

Rotational molding die for oil tank production

Technical Field

The application relates to the technical field of rotational molding production, in particular to a rotational molding die for oil tank production.

Background

The rotational molding die is a molding process of a thermoplastic hollow product, and can also be called rotational molding, rotational molding and the like. In the process of rotational molding a mold, a powdery or pasty raw material is injected into the mold, and the mold is heated while performing a rolling rotation in the longitudinal and transverse directions, so that the raw material is uniformly distributed over the inner cavity of the mold by the action of self gravity and centrifugal force and melted. And after cooling, demolding to obtain the hollow product.

The molding process has the characteristics of low input cost and simple mold development, and is widely applied to the production of oil tanks and oil drums, however, in the process of producing the oil tanks, some molds can only produce one product, and also some molds can be provided with partition plates to partition a cavity into a plurality of molding spaces so as to produce a plurality of products at one time, and the cavities of the molds are fixedly arranged, so that the formed product is single in form.

Disclosure of Invention

It is an object of the present application to provide a rotomoulding mould capable of producing one or more fuel tanks.

The rotational molding die for oil tank production adopts the following technical scheme:

the rotational molding die for producing the oil tank comprises an upper die, a lower die and a partition plate, wherein the upper die is detachably connected with the lower die to form a cavity, the upper die comprises a first die plate and a second die plate which are mutually connected, and an adjusting cavity is formed between the second die plate and the second die plate;

the lower die is rotationally connected with a partition plate for partitioning the cavity, a first forming sleeve and a second forming sleeve for forming the oil injection cylinder are arranged in the adjusting cavity, and the first forming sleeve slides relative to the second forming sleeve and pushes the partition plate to be abutted to the inner wall of the lower die.

Through adopting above-mentioned technical scheme, the partition panel can separate or not separate the die cavity, when the partition panel separates into two shaping regions with the die cavity, all inject the raw materials in two regions, with the less oil tank of shaping two sizes, when need not partition panel separate the die cavity, promote first forming sleeve, make the inner wall butt of partition panel and lower membrane, then with the raw materials injection to the die cavity in, with the great oil tank of shaping size, make the mould can select the great oil tank of shaping two oil tanks of sizes or one body type, have multiple shaping scheme, the product category of production is richer.

Optionally, a push rod is disposed between the partition plate and the first forming sleeve, the partition plate includes a first connecting plate and a second connecting plate, and the first connecting plate and the second connecting plate are connected with the first forming sleeve through the push rod.

Through adopting above-mentioned technical scheme, when first forming sleeve slides, push rod promotes first connecting plate and second connecting plate, make first connecting plate and second connecting plate all rotate towards keeping away from or being close to the central region of lower mould, through this kind of motion of opening the door and closing the door, control the partition panel and cut off the type chamber, with the product type of adjusting the mould production, and first forming sleeve itself makes its and die cavity intercommunication or not communicate through gliding mode too, the product type of adjusting the mould production, optimize two steps into a step, the operation is more convenient, be favorable to improving conversion efficiency.

Optionally, the push rod is arranged in the adjusting cavity, one side of the first connecting plate and one side of the second connecting plate, which is close to the upper die, are connected with connecting blocks, and the connecting blocks extend into the adjusting space and are connected with the push rod.

In rotational molding, the shape of the product is directly associated with the shape of the cavity, and by adopting the technical scheme, as the connecting block can extend into the adjusting space, the push rod can push the connecting block in the adjusting space to change the state of the partition plate, and compared with a mode of directly placing the push rod into the cavity, the influence of the push rod on the molded product is reduced.

Optionally, the second template is last seted up with the sliding tray that the connecting block matches, the connecting block includes the slider and encircles the first shutoff piece that the slider set up, first shutoff piece with the second template board is hugged closely and is blocked the peripheral region of sliding tray.

Because the push rod makes first connecting plate and second connecting plate rotate through promoting the connecting block, need open a groove in order to provide the slip path of first connecting plate and second connecting plate on the second template, when leading to carrying out rotational moulding, partial raw materials can get into in the regulation cavity, through adopting above-mentioned technical scheme, in the rotation in-process, be located the first shutoff piece of connecting block week side and can carry out the shutoff to the peripheral region of sliding tray to prevent the raw materials from getting into from the sliding tray, be favorable to guaranteeing the quality of product.

Optionally, the first forming sleeve is connected with a clamping plate for fixing the first forming sleeve, and the clamping plate can be sleeved on the second forming sleeve.

Through adopting above-mentioned technical scheme, after the cardboard inserts in the second forming sleeve, first forming sleeve is fixed by the second forming sleeve, and the partition panel of being connected with first forming sleeve no longer removes and keeps this position state this moment, prevents the partition panel removal through the mode of joint, has ensured the stability of two shaping regions.

Optionally, the partition panel with the lower mould rotates to be connected, set up the hidden groove on the lower mould inner wall, be provided with the shutoff board in the hidden groove, the partition panel promotes the shutoff board is followed the direction of seting up in hidden groove slides.

Through adopting above-mentioned technical scheme, when the partition panel cuts off the die cavity and is two shaping regions, the shutoff board stretches out from hiding the inslot this moment, and its lateral wall keeps flush with the lower mould lateral wall, and when the partition panel rotated no longer cuts off the die cavity, the partition panel finally promotes the shutoff board and gets into hiding the inslot and replace to the original position of shutoff board to when the arbitrary oil tank in two kinds of models of guarantee shaping, the oil tank outward appearance is smooth.

Optionally, the lower mould includes overcoat, endotheca and a plurality of fixed column, overcoat with the endotheca is through a plurality of fixed column fixed connection, set up the cooling mouth on the overcoat, the overcoat with form the cooling chamber between the endotheca, the cooling mouth with the cooling chamber intercommunication.

Through adopting above-mentioned technical scheme, connect through the fixed column between overcoat and the endotheca for have the clearance and then form the cooling chamber between overcoat and the endotheca, after the shaping of heating, pour into air current or rivers into in the cooling chamber from the cooling mouth, accelerate cooling rate.

Optionally, the inner sleeve includes first shaping board and second shaping board, set up the spacing groove on the second shaping board, the tip of first shaping board stretches into in the spacing groove and relative the second shaping board slides.

Through adopting above-mentioned technical scheme, sliding connection between first shaping board and the second shaping board, in the spacing groove of seting up through sliding first shaping board entering second shaping board, make the size shrink of die cavity to change the size of die cavity, the different oil tank of shaping specification is favorable to improving the variety of product.

Optionally, a sliding rod is arranged on the outer sleeve, and one end of the sliding rod extends into the cooling chamber and can push the first forming plate to move.

Through adopting above-mentioned technical scheme, when the size that needs to change the die cavity, promote the slide bar, make first shaping board slide relative to the second shaping board, wait to adjust to the suitable size after, the slide bar keeps the position state of second shaping board, changes the position of second shaping board through the slide bar, the simple operation, easy to carry out.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the die cavity of this application is provided with the partition panel in, the partition panel can separate or not separate the die cavity, when the partition panel separates into two shaping regions with the die cavity, all pour into the raw materials in two regions, with the less oil tank of shaping two sizes, when need not partition panel separate the die cavity, promote first forming sleeve, make the inner wall butt of partition panel and lower membrane, pour into the raw materials into in the die cavity afterwards, with the great oil tank of shaping size, make the mould can select the less oil tank of shaping two sizes or the great oil tank of a body type, have multiple shaping scheme, the product category of production is richer.

2. When the first forming sleeve slides, the push rod pushes the first connecting plate and the second connecting plate, so that the first connecting plate and the second connecting plate rotate towards a central area far away from or close to the lower die, the partition plate is controlled to partition the cavity through the movement of the door opening and closing modes, the product type produced by the die is regulated, the first forming sleeve is communicated or not communicated with the die cavity in a sliding mode, the product type produced by the die is regulated, the two steps are optimized into one step, the operation is more convenient, and the conversion efficiency is improved.

3. The clearance after the partition plate removes can be filled to the shutoff board in this application, when the partition plate cuts off the die cavity and is two shaping regions, the shutoff plate stretches out from hiding the inslot this moment, and its terminal surface keeps flush with the lower mould lateral wall, and when the partition plate rotated no longer cuts off the die cavity, the partition plate finally promotes the shutoff board and gets into hiding the inslot and replace to the original position of shutoff plate to when the arbitrary oil tank in two kinds of models of guarantee shaping, the oil tank outward appearance is smooth.

Drawings

FIG. 1 is a schematic perspective view of a rotational molding die for producing an oil tank;

FIG. 2 is a schematic diagram of the explosive structure of the upper die in the present application;

FIG. 3 is a schematic perspective view of the upper die in the present application;

FIG. 4 is a schematic perspective view of the lower die of the present application;

FIG. 5 is a schematic cross-sectional view of the lower die of the present application;

fig. 6 is an enlarged partial schematic view of the portion a in fig. 5.

In the figure, 1, an upper die; 11. a first template; 12. a second template; 121. a sliding groove; 122. a feed inlet; 13. adjusting the cavity; 2. a lower die; 21. a hidden groove; 22. a jacket; 221. a cooling port; 23. an inner sleeve; 231. a first molding plate; 2311. a limit groove; 232. a second molding plate; 233. a guide rod; 24. fixing the column; 25. a cooling chamber; 3. a cavity; 4. a partition panel; 41. a first connection plate; 42. a second connecting plate; 5. a first forming sleeve; 6. a second molding jacket; 7. a push rod; 8. a connecting block; 81. a slide block; 82. a first blocking piece; 9. a clamping plate; 91. a fixing plate; 92. a fixing groove; 10. a plugging plate; 20. a slide bar; 30. a second blocking piece; 40. an elastic element.

Detailed Description

The present application is described in further detail below with reference to fig. 1-6.

The rotational molding die for oil tank production is referenced in fig. 1 and 2, and comprises an upper die 1 and a lower die 2, wherein the upper die 1 and the lower die 2 are detachably connected to form a cavity 3, a first forming sleeve 5 and a second forming sleeve 6 for forming an oil injection cylinder are connected to the upper die 1, a partition plate 4 for partitioning the cavity 3 is rotationally connected to the lower die 2 in a rotating manner in combination with fig. 3 and 4, and the first forming sleeve 5 slides relative to the second forming sleeve 6 and pushes the partition plate 4 to be in butt joint with the inner wall of the lower die 2.

Referring to fig. 2 and 3, the upper mold 1 includes a first mold plate 11 and a second mold plate 12 connected to each other, and the bottom side of the second mold plate 12 is matched to the shape of the fuel tank, wherein a space is maintained between the first mold plate 11 and the second mold plate 12 to form an adjustment cavity 13, and the first molding sleeve 5 and the second molding sleeve 6 are disposed in the adjustment cavity 13.

When the oil tank is formed, the upper die 1 part needs to be arranged into a shape matched with an oil injection cylinder of the oil tank, namely, a first forming sleeve 5 and a second forming sleeve 6 for forming the oil injection cylinder, only one forming sleeve is needed for forming one oil tank, when the partition plate 4 is converted from a plugging cavity 3 to a form without plugging the cavity 3, the first forming sleeve 5 slides and is not communicated with the cavity 3 any more, and is driven by the first forming sleeve 5, and the partition plate 4 rotates and is abutted against the inner wall of the lower die 2.

The second template 12 is provided with a feed inlet 122 matched with the first molding sleeve 5 and the second molding sleeve 6, the first molding sleeve 5 and the second molding sleeve 6 are both communicated with the cavity 3 through the feed inlet 122, in addition, in order to prevent the first molding sleeve 5 from sliding, raw materials enter into an adjusting space from the feed inlet 122, the first molding sleeve 5 is provided with a second sealing piece 30 in a surrounding mode, the second sealing piece 30 is tightly attached to the wall surface of the second template 12, and when the first molding sleeve 5 slides, the second sealing piece 30 seals the feed inlet 122.

Referring to fig. 4 and 5, the lower die 2 includes an outer jacket 22, an inner jacket 23 and a plurality of fixing columns 24, the outer jacket 22 and the inner jacket 23 are fixedly connected through the plurality of fixing columns 24, a cooling port 221 is formed on the outer jacket 22, a cooling chamber 25 is formed between the outer jacket 22 and the inner jacket 23, the cooling port 221 is communicated with the cooling chamber 25, and when a product is cooled, low-temperature gas or liquid is injected into the cooling chamber 25 from the cooling port 221 so as to accelerate the cooling speed and facilitate the next demoulding operation.

Referring to fig. 4 and 5, the inner sleeve 23 includes a first molding plate 231 and a second molding plate 232, the number of the first molding plate 231 and the second molding plate 232 is two, wherein the two first molding plates 231 are oppositely arranged along the length direction of the inner sleeve 23, the two second molding plates 232 are oppositely arranged along the width direction of the inner sleeve 23, two ends of the first molding plate 231 are arc-shaped, a limiting groove 2311 is formed in the second molding plate 232, and the end part of the first molding plate 231 extends into the limiting groove 2311 and slides relative to the second molding plate 232, and two ends of the first molding plate 231 are respectively inserted into the limiting grooves 2311 formed on the same side of the two second molding plates 232.

Referring to fig. 4, a slide bar 20 is disposed on the outer sleeve 22, one end of the slide bar 20 extends into the cooling chamber 25 and can push the first molding plate 231 to move, correspondingly, a limiting hole for the slide bar 20 to pass through is formed on the outer sleeve 22, and when the shape of the cavity 3 needs to be changed, the slide bar 20 is pushed to adjust the length of the first molding plate 231 extending into the limiting groove 2311.

Referring to fig. 5 and 6, an elastic element 40 is disposed in the limit slot 2311, one end of the elastic element 40 is abutted against the inner wall of the limit slot 2311, the other end of the elastic element 40 is abutted against the end of the first molding plate 231, when the slide bar 20 no longer applies force to the first molding plate 231, the elastic element 40 rebounds, the cavity 3 returns to the original size, further, in order to improve the sliding stability of the first molding plate 231 relative to the second molding plate 232, a plurality of guide rods 233 are disposed on the first molding plate 231, in this embodiment, two guide holes matched with the guide rods 233 are correspondingly formed on the second molding plate 232, and it should be noted that, in this embodiment, springs are used for the elastic elements.

Referring to fig. 4 and 5, the partition plate 4 includes a first connection plate 41 and a second connection plate 42, the first connection plate 41 and the second connection plate 42 being disposed opposite to each other in the width direction of the lower die 2 and hinged with the inner sleeve 23, the first connection plate 41 and the second connection plate 42 being each in driving connection with the first molding sleeve 5 through the push rod 7.

When the partition plate 4 partitions the cavity 3, the first connecting plate 41 and the second connecting plate 42 are parallel to the width direction of the lower die 2, and when the partition plate 4 does not partition the cavity 3, the side walls of the first connecting plate 41 and the second connecting plate 42 are abutted against the inner wall of the lower die 2, and the first connecting plate 41 and the second connecting plate 42 are parallel to the length direction of the lower die 2, in other words, the combination of the first connecting plate 41 and the second connecting plate 42 forms an action of opening and closing the door so as to partition or not partition the cavity 3, and the specification of the production oil tank is adapted according to the requirement.

Referring to fig. 4, a hidden groove 21 is formed on the inner wall of the inner sleeve 23, hinge parts of the first connecting plate 41 and the second connecting plate 42 and the inner sleeve 23 are all placed in the hidden groove 21, a plugging plate 10 is disposed in the hidden groove 21, in this embodiment, the specification size of the plugging plate 10 is the same as the specification size of the first connecting plate 41 and the second connecting plate 42, an elastic element 40 is disposed between the plugging plate 10 and the bottom wall of the hidden groove 21, one end of the elastic element 40 is connected with the plugging plate 10, the other end of the elastic element 40 is connected with the bottom wall of the hidden groove 21, and the first connecting plate 41 pushes the plugging plate 10 to slide along the opening direction of the hidden groove 21.

When the first connecting plate 41 and the second connecting plate 42 are combined to partition the cavity 3, the plugging plates 10 extend out of the hidden groove 21, the side surfaces of the plugging plates 10 are kept flush with the side walls of the inner sleeve 23, and the end surfaces of the two plugging plates 10 are respectively abutted against the side walls of the first connecting plate 41 and the second connecting plate 42.

When the first connecting plate 41 and the second connecting plate 42 do not partition the cavity 3 any more, the first connecting plate 41 and the second connecting plate 42 are rotated at this time, and in the rotating process, the first connecting plate 41 and the second connecting plate 42 press the corresponding plugging plate 10 to retract the plugging plate 10 into the hidden groove 21, and the side surfaces of the first connecting plate 41 and the second connecting plate 42 are kept flush with the side wall of the inner sleeve 23 to keep the outside of the formed oil tank smooth.

When the first connecting plate 41 and the second connecting plate 42 are operated to block the cavity 3, the elastic element 40 pushes the plugging plate 10 to extend out of the hidden groove 21.

Referring to fig. 2 and 3, in order to maintain the stability that the side surfaces of the first and second connection plates 41 and 42 are kept flush with the side wall of the inner sleeve 23, the first molding sleeve 5 is connected with a clamping plate 9 for fixing the first molding sleeve 5, the clamping plate 9 can be sleeved on the second molding sleeve 6, specifically, the clamping plate 9 includes two fixing plates 91 rotating relative to the first molding plate 231, fixing grooves 92 are formed in the fixing plates 91, the two fixing grooves 92 are semi-annular, when the two fixing plates 91 are spliced together after rotating, the two fixing grooves 92 are combined to form a restraining hole, the aperture size of the restraining hole is matched with the outer diameter of the second molding sleeve 6, and then bolts are inserted to fasten.

Referring to fig. 2 and 3, a push rod 7 is disposed between the partition plate 4 and the first molding sleeve 5, two ends of the push rod 7 are respectively connected with the partition plate 4 and the first molding sleeve 5 in a rotating manner, the push rod 7 is disposed in the adjusting space, correspondingly, one side, close to the upper die 1, of the first connecting plate 41 and the second connecting plate 42 is connected with a connecting block 8, the connecting block 8 stretches into the adjusting space and is connected with the push rod 7, the number of the push rods 7 is two, one ends of the two push rods 7 are respectively connected with the first molding sleeve 5 in a rotating manner, and the other ends of the two push rods 7 are arranged in one-to-one correspondence with the two connecting blocks 8.

The second template 12 is provided with a sliding groove 121 matched with the connecting block 8, the sliding groove 121 is in a quarter ring shape, the connecting block 8 comprises a sliding block 81 and a first blocking piece 82 arranged around the sliding block 81, the first blocking piece 82 is tightly attached to the second template 12 and blocks the peripheral area of the sliding groove 121, and when the sliding block 81 moves, the first blocking piece 82 blocks the peripheral area of the sliding groove 121 so as to prevent the condition that the adjusting cavity 13 is communicated with the cavity 3 and then raw materials enter the adjusting cavity 13.

The implementation principle of the embodiment of the application is as follows: when two smaller oil tanks are required to be molded simultaneously, the first molding sleeve 5 is pushed to the right upper end of the feeding port 122, at the moment, the first connecting plate 41 and the second connecting plate 42 are combined to partition the cavity 3, the cavity 3 is divided into two molding areas, raw materials are injected into the two areas to mold the two oil tanks, after the inner wall of the cavity 3 is full of the raw materials, water or air is injected into the cooling port 221, and then demolding is carried out, so that a product is obtained;

when a large-size oil tank needs to be formed, the first forming sleeve 5 is pushed to approach the second forming sleeve 6 until the first forming sleeve is clamped with the second forming sleeve 6, at the moment, the feed inlet 122 is blocked by the second blocking piece 30, then raw materials are injected into the cavity 3, the raw materials only enter the second forming sleeve 6 to form an oil injection cylinder, in the moving process of the first forming sleeve 5, the push rod 7 pushes the first connecting plate 41 and the second connecting plate 42 to move towards the side wall, close to the inner sleeve 23, along the length direction, of the first connecting plate 41 and the second connecting plate 42, in the moving process, the blocking plate 10 is pushed to retract into the hiding groove 21, so that the side walls of the first connecting plate 41 and the second connecting plate 42 are in smooth transition with the inner wall of the inner sleeve 23, and the formed oil tank is ensured to be smooth in appearance;

the number of the oil injection barrels formed is changed by sliding the first forming sleeve 5, in the changing process, the first forming sleeve 5 also pushes the partition plate 4 to plug or not plug the cavity 3, so that the die can selectively form two smaller oil tanks or one larger oil tank, in addition, the sliding rod 20 can be pushed, at the moment, the first forming plate 231 slides towards the second forming plate 232, the cavity 3 is contracted, the size of the cavity 3 is changed, the oil tanks with different forming specifications are changed, and the produced products are richer.

The embodiments of this embodiment are all preferred embodiments of the present application, and are not intended to limit the scope of the present application, in which like parts are denoted by like reference numerals. Therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims (9)

1. The rotational molding die for producing the oil tank comprises an upper die (1) and a lower die (2), and is characterized in that the upper die (1) is detachably connected with the lower die (2) to form a cavity (3), the upper die (1) comprises a first die plate (11) and a second die plate (12) which are mutually connected, and an adjusting cavity (13) is formed between the second die plate (12) and the second die plate (12);

the lower die (2) is rotationally connected with a partition board (4) for partitioning the cavity (3), a first forming sleeve (5) and a second forming sleeve (6) for forming the oil injection cylinder are arranged in the adjusting cavity (13), and the first forming sleeve (5) slides relative to the second forming sleeve (6) and pushes the partition board (4) to be abutted against the inner wall of the lower die (2).

2. Rotational moulding die for oil tank production according to claim 1, characterized in that a push rod (7) is arranged between the partition plate (4) and the first forming sleeve (5), the partition plate (4) comprises a first connecting plate (41) and a second connecting plate (42), and the first connecting plate (41) and the second connecting plate (42) are connected with the first forming sleeve (5) through the push rod (7).

3. Rotational molding die for oil tank production according to claim 2, characterized in that the push rod (7) is arranged in the adjusting cavity (13), one side of the first connecting plate (41) and one side of the second connecting plate (42) close to the upper die (1) are respectively connected with a connecting block (8), and the connecting blocks (8) extend into the adjusting space and are connected with the push rod (7).

4. A rotational moulding mould for oil tank production according to claim 3, characterized in that the second mould plate (12) is provided with a sliding groove (121) matched with the connecting block (8), the connecting block (8) comprises a sliding block (81) and a first blocking piece (82) arranged around the sliding block (81), and the first blocking piece (82) is tightly attached to the second mould plate (12) and blocks the peripheral area of the sliding groove (121).

5. Rotational molding die for oil tank production according to claim 1, characterized in that the first molding sleeve (5) is connected with a clamping plate (9) for fixing the first molding sleeve (5), and the clamping plate (9) can be sleeved on the second molding sleeve (6).

6. The rotational molding die for oil tank production according to claim 1, wherein the partition plate (4) is rotationally connected with the lower die (2), a hidden groove (21) is formed in the inner wall of the lower die (2), a blocking plate (10) is arranged in the hidden groove (21), and the partition plate (4) pushes the blocking plate (10) to slide along the opening direction of the hidden groove (21).

7. The rotational molding die for oil tank production according to claim 1, wherein the lower die (2) comprises an outer sleeve (22), an inner sleeve (23) and a plurality of fixing columns (24), the outer sleeve (22) and the inner sleeve (23) are fixedly connected through the plurality of fixing columns (24), a cooling opening (221) is formed in the outer sleeve (22), a cooling chamber (25) is formed between the outer sleeve (22) and the inner sleeve (23), and the cooling opening (221) is communicated with the cooling chamber (25).

8. The rotational molding die for producing the oil tank according to claim 7, wherein the inner sleeve (23) comprises a first molding plate (231) and a second molding plate (232), a limiting groove (2311) is formed in the second molding plate (232), and the end portion of the first molding plate (231) extends into the limiting groove (2311) and slides relative to the second molding plate (232).

9. A rotomoulding mould for producing fuel tanks according to claim 8, characterized in that the jacket (22) is provided with slide bars (20), one end of the slide bars (20) extending into the cooling chamber (25) and being able to push the first forming plate (231) to move.