阅读说明：本技术 吹塑机的脉动式冷却吹气装置及其吹气方法 (Pulsating cooling blowing device of blow molding machine and blowing method thereof ) 是由 徐文良 林一波 何建领 肖志林 于 2020-07-16 设计创作，主要内容包括：一种吹塑机的脉动式冷却吹气装置及其吹气方法,步骤：熔融的塑料型坯进入模具后,由第一、第二吹针将塑料型坯撑开,模具开始合模,压力气源装置工作而将压力空气供给吹气总系统,吹气总系统包括吹气气路和控制气路；在料坯撑开到位,开始低压吹气,吹气结束后,切换到高压吹气；气经第一分配气路的高压气路,再经第一调压阀及第一角座阀后分成第一和第二吹气路向模具内吹气；保压结束后,第二吹气路为通气路,第一吹气路为放气通路,第一消音器通并开始放气,第一吹气路为常通气路,第二吹气路为放气路,第二消音器通并开始放气。简化结构,方便配置；满足短时间内频繁启动且反应灵敏的要求；动作可靠；提高热交换效率,减少能耗及减小噪声。(A pulsating cooling blowing device of a blow molding machine and a blowing method thereof comprise the following steps: after the molten plastic parison enters a mold, the plastic parison is spread by a first blowing needle and a second blowing needle, the mold starts to be closed, a pressure air source device works to supply pressure air to an air blowing main system, and the air blowing main system comprises an air blowing air path and a control air path; when the blank is opened in place, low-pressure blowing is started, and after blowing is finished, high-pressure blowing is switched; the air passes through a high-pressure air path of the first distribution air path, then passes through a first pressure regulating valve and a first angle seat valve and then is divided into a first air blowing path and a second air blowing path to blow air into the mold; after the pressurize is finished, the second blows the gas circuit for the gas circuit, and first blowing gas circuit is the gassing route, and first muffler leads to and begins the gassing, and first blowing gas circuit is normal open gas circuit, and the second blows the gas circuit for putting the gas circuit, and the second muffler leads to and begins the gassing. The structure is simplified, and the configuration is convenient; the requirements of frequent starting and sensitive reaction in a short time are met; the action is reliable; the heat exchange efficiency is improved, the energy consumption is reduced, and the noise is reduced.)

1. A pulsating cooling blowing device of a blow molding machine is characterized by comprising a pressure air source device (1) and a blowing main system (2), wherein the pressure air source device (1) is connected with the blowing main system (2) through a pipeline, the blowing main system (2) comprises a blowing air path (21) and a control air path (22), an air filtering and pressure regulating device (211) is arranged on the blowing air path (21), and a pressure regulating, filtering and drying device (221) is arranged on the control air path (22); the first electromagnetic valve I (3a), the second electromagnetic valve II (3b), the third electromagnetic valve III (3c), the fourth electromagnetic valve IV (3d), the fifth electromagnetic valve V (3e) and the sixth electromagnetic valve VI (3f) are connected on the control air path (22); the first distribution air path I (4) comprises a high-pressure path (41) and a low-pressure path (42), the high-pressure path (41) and the low-pressure path (42) are connected with one end, led out of the air filtering and pressure regulating device (211), of the blowing air path (21), a first pressure regulating valve I (411) and a first angle seat valve I (412) are connected to the high-pressure path (41), the first angle seat valve I (412) is connected with the first electromagnetic valve I (3a), a second pressure regulating valve II (421) and a second angle seat valve II (422) are connected to the low-pressure path (42), and the second angle seat valve II (422) is connected with the second electromagnetic valve II (3 b); a second distribution gas path II (5), the second distribution gas path II (5) including a first blowing path I (51) and a second blowing path II (52), one end of each of the first blowing path I (51) and the second blowing path II (52) being connected to the first distribution gas path I (4), the other end of each of the first blowing path I (51) and the second blowing path II (52) being connected to the first blowing needle I (6a) and the second blowing needle II (6b), respectively, the first blowing path I (51) being provided with a third seat valve III (511), the third seat valve III (511) being connected to the third electromagnetic valve III (3c), the second blowing path II (52) being provided with a fourth seat valve IV (521), the fourth seat valve IV (521) being connected to the fourth electromagnetic valve IV (3d), the first blowing path I (51) being further provided with a fifth seat valve V (512), the fifth angle seat valve V (512) is connected with the fifth electromagnetic valve V (3e), a first silencer I (7a) is connected to the fifth angle seat valve V (512), a sixth angle seat valve VI (522) is further arranged on the second air blowing channel II (52), the sixth angle seat valve VI (522) is connected with the sixth electromagnetic valve VI (3f), and a second silencer II (7b) is connected to the sixth angle seat valve VI (522).

2. Pulsating cooling blower as claimed in claim 1, characterised in that the pressurized air supply device (1) is an air compressor or an air supply pump.

3. The pulsating cooling and blowing apparatus of a blow molding machine as claimed in claim 1, wherein said air filtering pressure adjusting means (211) comprises an air filter (2111), a pressure reducing valve (2112) and an oil mist device (2113), said pressure reducing valve (2112) is located between said air filter (2111) and said oil mist device (2113), and said air filter (2111) is located at an end of said blowing air path (21) facing said pressurized air source device (1), said high pressure channel (41) and said low pressure channel (42) are connected to an end of said blowing air path (21) facing said oil mist device (2113).

4. Pulsating cooling blowing device in blow molding machines according to claim 1, characterized in that the pressure-regulating filtering and drying device (221) comprises a pressure-regulating valve (2211) and an air filter (2212) arranged to the left and right of each other on the control air circuit (22).

5. The pulsating cooling blowing device of the blow molding machine as claimed in claim 1, characterized in that a first pressure indicator i (413) is arranged on the high-pressure air path (41) and at a position between the first pressure regulating valve i (411) and the first angle seat valve i (412); and a second pressure indicator II (423) is arranged on the low-pressure air passage (42) and at a position between the second pressure regulating valve II (421) and the second angle seat valve II (422).

6. The pulsating cooling blowing device of the blow molding machine as claimed in claim 4, characterized in that a pressure display (222) is provided on the control gas circuit (22) and at a position to the right of the pressure regulator (2211).

7. A blowing method for a pulsating cooling blowing device of a blow molding machine as claimed in claim 1, characterized by comprising the steps of:

A) in an initial state, after a molten plastic parison enters a mold (8), the plastic parison is spread by a first blowing needle I (6a) and a second blowing needle II (6b), the mold (8) starts to be closed, a pressure air source device (1) works to connect a pressure air supply pipeline with an air blowing total system (2), and the air blowing total system (2) comprises an air blowing air path (21) and a control air path (22);

B) low-pressure blowing, wherein the blank is expanded to a proper position, low-pressure blowing is started, a second electromagnetic valve II (3b), a third electromagnetic valve III (3c) and a fourth electromagnetic valve IV (3d) which are connected with a control air path (22) are electrified, a second angle seat valve II (422), a third angle seat valve III (511) and a fourth angle seat valve IV (521) form a passage, the other electromagnetic valves are in a power-off state, air passes through a low-pressure air path (42) of a first distribution air path I (4), then passes through a second pressure regulating valve II (421) and a second angle seat valve II (422), then is divided into a first blowing air path I (51) and a second blowing air path II (52) of a second distribution air path II (5), and is blown into a mold (8) by a first blowing needle I (6a) and a second blowing needle II (6b) at the same time, and after blowing is finished, high-pressure blowing is switched;

C) high-pressure blowing, wherein a first electromagnetic valve I (3a), a third electromagnetic valve III (3c) and a fourth electromagnetic valve IV (3d) which are connected with a control air path (22) are electrified, a first angle seat valve I (412), a third angle seat valve III (511) and a fourth angle seat valve IV (521) form a passage, other electromagnetic valves are in a power-off state, air passes through a high-pressure air path (41) of a first distribution air path I (4), then passes through a first pressure regulating valve I (411) and the first angle seat valve I (412), is divided into a first blowing air path I (51) and a second blowing air path II (52), and is simultaneously blown into a mold (8) by a first blowing needle I (6a) and a second blowing needle II (6b), the blowing time is controlled, and the pressure is maintained after the blowing is finished;

D) deflating, after the pressure maintaining in the step C) is finished, energizing the first electromagnetic valve I (3a), switching on the first angle seat valve I (412), enabling the high-pressure air passage (41) to be a normal passage, energizing the fourth electromagnetic valve IV (3d) and the fifth electromagnetic valve V (3e), enabling the second air blowing passage II (52) to be an air passage, the first air blowing path I (51) becomes an air discharging path, the fifth angle seat valve V (512) is opened, the first silencer I (7a) is opened and starts to discharge air, after a period of time, the fourth solenoid valve IV (3d) and the fifth solenoid valve V (3e) are closed, the third solenoid valve III (3c) and the sixth solenoid valve VI (3f) are opened, the sixth seat valve VI (522) is communicated, the first air blowing channel I (51) becomes a normal-open air channel, and the second blowing path II (52) becomes an air release path, and the second muffler II (7b) is opened and starts air release.

8. The blowing method for a pulse cooling blower of a blow molding machine according to claim 7, wherein the control of the blowing time in step C) is a control of the blowing time to 40-70 s.

9. Blowing method of a pulsating cooling blowing device of a blow molding machine according to claim 7, characterized in that the dwell pressure in step C) is 0.6-0.8MPa and the dwell time is 10-20 s.

Technical Field

The invention belongs to the technical field of hollow plastic product molding, and particularly relates to a pulsating cooling and blowing device of a blow molding machine, and a blowing method thereof.

Background

The above-mentioned blow molding machines can be found in published chinese patent documents such as CN201941151U recommended by "full-automatic blow molding machine for plastic containers" and CN202162995U provided with "full-automatic blow molding machine for large plastic containers", and so on. From a reading of the patent literature, which is not limited to the above list, and in combination with general knowledge: the hollow molding machine functions to obtain hollow plastic containers by blowing, such as packaging barrels, water tanks, oil tanks, various stacking barrels, tubular members, and the like, for filling medical and chemical raw materials, oil products, various additives, various solvents, additives, hazardous chemicals, and the like.

The aforesaid blowing device is a component of the whole structural system of the blow molding machine and is also found in the published chinese patent literature, typically "a blowing system of the blow molding machine and blowing process thereof" introduced in CN109702993A, which can embody the technical effects described in paragraph 0014 of the specification, but in terms of structure, because the used air source is a compressed air freezing device, and because a liquid atomizing mechanism and the like are needed, the structure is relatively complex, which is not only unfavorable for manufacturing and using, but also inconvenient for energy saving; in the method (referred to as "process"), the process is lengthy and the desired blow molding efficiency cannot be achieved because the steps of initial state, blow pin head cooling, parison inflation, high pressure molding, high pressure ventilation heat removal, atomization cooling, blow drying, and exhaust are required in sequence. In view of the foregoing, there is a need for reasonable improvements, and the solutions described below are made in this context.

Disclosure of Invention

The invention provides a pulsating cooling and blowing device of a blow molding machine, which is convenient to arrange in the blow molding machine and use, has excellent control effect, can be frequently started in a short time, is sensitive in response, is beneficial to ensuring the reliability of action, can realize ideal pulsating blowing effect, is convenient to perform blowing and exhausting circulation when a product is cooled and blown, can exhaust heat in the product to the outside, can improve heat exchange efficiency, can reduce the consumption of compressed air and reduce noise.

Another object of the present invention is to provide a blowing method for a pulsating cooling blower of a blow molding machine, which is helpful for significantly shortening the process flow to improve the production efficiency of products, and to meet the requirement of industrial scale-up production, and is helpful for ensuring that the technical effects of the pulsating cooling blower are fully embodied.

The invention has the following main tasks that the pulsating cooling and blowing device of the blow molding machine comprises a pressure air source device and a blowing main system, wherein the pressure air source device is connected with the blowing main system through a pipeline; the first electromagnetic valve I, the second electromagnetic valve II, the third electromagnetic valve III, the fourth electromagnetic valve IV, the fifth electromagnetic valve V and the sixth electromagnetic valve VI are connected to the control gas path; the first distribution pipeline I comprises a high-pressure pipeline and a low-pressure pipeline, the high-pressure pipeline and the low-pressure pipeline are connected with one end, led out of the air filtering and pressure regulating device, of the air blowing pipeline, a first pressure regulating valve I and a first angle seat valve I are connected to the high-pressure pipeline, the first angle seat valve I is connected with the first electromagnetic valve I, a second pressure regulating valve II and a second angle seat valve II are connected to the low-pressure pipeline, and the second angle seat valve II is connected with the second electromagnetic valve II; a second distribution gas path II, which comprises a first gas blowing path I and a second gas blowing path II, one end of the first gas blowing path I and one end of the second gas blowing path II are both connected with the first gas blowing path I, the other end of the first gas blowing path I and the other end of the second gas blowing path II are respectively connected with a first blowing needle I and a second blowing needle II, a third angle seat valve III is arranged on the first gas blowing path I, the third angle seat valve III is connected with a third electromagnetic valve III, a fourth angle seat valve IV is arranged on the second gas blowing path II, the fourth angle seat valve IV is connected with a fourth electromagnetic valve IV, a fifth angle seat valve V is arranged on the first gas blowing path I, the fifth angle seat valve V is connected with the fifth electromagnetic valve V, a first silencer I is connected on the fifth angle seat valve V, and a first hexagonal seat valve VI is arranged on the second gas blowing path, the sixth solenoid valve VI is connected with the sixth solenoid valve VI, and a second silencer II is connected to the sixth solenoid valve VI.

In a specific embodiment of the present invention, the pressurized air source device is an air compressor or an air supply pump.

In another specific embodiment of the present invention, the air filtering pressure regulating device includes an air filter, a pressure reducing valve and an oil mist device, the pressure reducing valve is located between the air filter and the oil mist device, the air filter is located at one end of the blowing air path facing the pressure air source device, and the high pressure road and the low pressure road are connected to one end of the blowing air path out of the oil mist device.

In another embodiment of the present invention, the pressure-regulating filtering and drying device includes a pressure-regulating valve and an air filter which are disposed on the control air path in a left-right direction with respect to each other.

In a further specific embodiment of the invention, a first pressure indicator I is arranged on the high-pressure gas path and at a position between the first pressure regulating valve I and the first angle seat valve I; and a second pressure indicator II is arranged on the low-pressure air path and between the second pressure regulating valve II and the second angle seat valve II.

In yet another specific embodiment of the invention, a pressure display is provided on the control gas path and at a position to the right of the pressure regulator.

Another object of the invention is achieved by a blowing method for a pulsating cooling blower of a blow molding machine, comprising the following steps:

A) in the initial state, after a molten plastic parison enters a mold, the plastic parison is spread by a first blowing needle I and a second blowing needle II, the mold starts to be closed, a pressure air source device works to supply pressure air to an air blowing total system connected with a pipeline, and the air blowing total system comprises an air blowing air path and a control air path;

B) low-pressure blowing, namely starting low-pressure blowing when the blank is in place, electrifying a second electromagnetic valve II, a third electromagnetic valve III and a fourth electromagnetic valve IV which are connected with a control gas circuit, enabling a second angle seat valve II, a third angle seat valve III and a fourth angle seat valve IV to be paths, enabling the rest electromagnetic valves to be in a power-off state, enabling the gas to pass through a low-pressure gas circuit of a first distribution gas circuit I, then pass through a second pressure regulating valve II and the second angle seat valve II, then be divided into a first blowing gas circuit I and a second blowing gas circuit II of a second distribution gas circuit II, simultaneously blowing the gas into the mold by a first blowing needle I and a second blowing needle II, and switching to high-pressure blowing after the blowing is finished;

C) the high-pressure air blowing device comprises a control air path, a first solenoid valve I, a third solenoid valve III and a fourth solenoid valve IV which are connected with the control air path are electrified, the first angle seat valve I, the third angle seat valve III and the fourth angle seat valve IV form a path, other solenoid valves are in a power-off state, air passes through a high-pressure air path of a first distributing air path I, then passes through a first pressure regulating valve I and the first angle seat valve I, is divided into a first air blowing path I and a second air blowing path II, and is blown into a mold by a first air blowing needle I and a second air blowing needle II at the same time, the air blowing time is controlled, and the pressure is maintained after the air;

D) and (C) deflating, after the pressure maintaining is finished, the first electromagnetic valve I is powered on, the first angle seat valve I is switched on, the high-pressure air passage becomes a normal passage, the fourth electromagnetic valve IV d and the fifth electromagnetic valve V are powered on, the second air blowing passage II becomes an air passing passage, the first air blowing passage I becomes an air bleeding passage, the fifth angle seat valve V is opened, the first silencer I is switched on and begins to deflate, after a period of time, the fourth electromagnetic valve IV and the fifth electromagnetic valve V are closed, the third electromagnetic valve III and the sixth electromagnetic valve VI are opened, the sixth angle seat valve VI is switched on, the first air blowing passage I becomes a normal passage, the second air blowing passage II becomes an air bleeding passage, and the second silencer II is switched on and begins to deflate.

In a more specific embodiment of the present invention, the air-blowing time is controlled to 40-70s in step C).

In a further particular embodiment of the invention, the dwell pressure in step C) is between 0.6 and 0.8MPa and the dwell time is between 10 and 20 s.

The technical scheme provided by the invention has the technical effects that: because the compressed air refrigerating device, the liquid atomizing mechanism and the like are not needed, the structure is simplified, and the device can be conveniently arranged on the blow molding machine and can be conveniently used; because the solenoid valve controls the angle seat valve, the requirements of frequent starting and sensitive response in a short time can be met; the gas circuit structure is reasonable, and the arrangement of the electromagnetic valve and the angle seat valve is optimized, so that the reliability of action is guaranteed and an ideal pulsation effect is realized; because the exhaust circulation is carried out when the product is cooled and blown, the heat in the product is exhausted to the outside, the heat exchange efficiency can be improved, the consumption of compressed air can be reduced, and the noise can be reduced; the blowing method provided helps to shorten the process flow significantly, thereby improving the production efficiency and meeting the requirements of industrial scale-up production and comprehensively representing the technical effect of the pulsating cooling blowing device of the blow molding machine.

Drawings

Fig. 1 is a schematic view of a pulsating cooling blowing device of a blow molding machine according to the invention.

Detailed Description

Referring to fig. 1, a pressure air source device 1 and an air blowing main system 2 are shown, the pressure air source device 1 is connected with the air blowing main system 2 through a pipeline, the air blowing main system 2 comprises an air blowing air path 21 and a control air path 22, an air filtering and pressure regulating device 211 is arranged on the air blowing air path 21, and a pressure regulating filtering and drying device 221 is arranged on the control air path 22; a first electromagnetic valve I3 a, a second electromagnetic valve II 3b, a third electromagnetic valve III 3c, a fourth electromagnetic valve IV 3d, a fifth electromagnetic valve V3 e and a sixth electromagnetic valve VI 3f are shown, wherein the first electromagnetic valve I3 a, the second electromagnetic valve II 3b, the third electromagnetic valve III 3c, the fourth electromagnetic valve IV 3d, the fifth electromagnetic valve V3 e and the sixth electromagnetic valve VI 3f are connected to the control gas circuit 22; a first distribution air path i 4 is shown, the first distribution air path i 4 comprises a high pressure path 41 and a low pressure path 42, the high pressure path 41 and the low pressure path 42 are connected with one end of the blowing air path 21 leading out of the air filtering and pressure regulating device 211, the high pressure path 41 is connected with a first pressure regulating valve i 411 and a first angle seat valve i 412, the first angle seat valve i 412 is connected with the first electromagnetic valve i 3a, the low pressure path 42 is connected with a second pressure regulating valve ii 421 and a second angle seat valve ii 422, and the second angle seat valve ii 422 is connected with the second electromagnetic valve ii 3 b; a second distribution gas path ii 5 is shown, the second distribution gas path ii 5 includes a first blowing gas path i 51 and a second blowing gas path ii 52, one end of each of the first blowing gas path i 51 and the second blowing gas path ii 52 is connected to the first distribution gas path i 4, the other end of each of the first blowing gas path i 51 and the second blowing gas path ii 52 is connected to the first blowing needle i 6a and the second blowing needle ii 6b, a third seat valve iii 511 is provided on the first blowing gas path i 51, the third seat valve iii 511 is connected to the third solenoid valve iii 3c, a fourth seat valve iv 521 is provided on the second blowing gas path ii 52, the fourth seat valve iv 521 is connected to the fourth solenoid valve iv 3d, a fifth seat valve v 512 is provided on the first blowing gas path i 51, the fifth seat valve v 512 is connected to the fifth solenoid valve v 3e, and a first muffler i 7a is connected to the fifth seat valve v 512, the second blowing path ii 52 is further provided with a sixth seat valve vi 522, the sixth seat valve vi 522 is connected to the sixth electromagnetic valve vi 3f, and the sixth seat valve vi 522 is connected to a second muffler ii 7 b.

In the present embodiment, the pressure air source device 1 is an air compressor, but an air supply pump that can generate pressure air may be used.

Continuing with fig. 1, the air filtering pressure regulating device 211 includes an air filter 2111, a pressure reducing valve 2112 and an oil mist device 2113, the pressure reducing valve 2112 is located between the air filter 2111 and the oil mist device 2113, the air filter 2111 is located on the blowing path 21 at an end of the blowing path facing the pressure air source device 1, and the high pressure passage 41 and the low pressure passage 42 are connected to an end of the blowing path 21, which end exits from the oil mist device 2113.

The pressure-regulating filtering and drying device 221 includes a pressure-regulating valve 2211 and an air filter 2212, which are disposed on the left and right of each other on the control air path 22.

Preferably, a first pressure indicator i 413 is provided on the high pressure path 41 at a position between the first pressure regulating valve i 411 and the first angle seat valve i 412; a second pressure indicator ii 423 is provided in the low-pressure gas passage 42 at a position between the second regulator valve ii 421 and the second seat valve ii 422.

Preferably, a pressure display 222 is disposed on the control gas path 22 and at a position right to the pressure regulator 2211.

The blowing method of the pulsating cooling blowing device of the blow molding machine shown in fig. 1 comprises the following steps:

A) in an initial state, after a molten plastic parison enters a mold 8, the plastic parison is spread to a certain width by a first blowing needle i 6a and a second blowing needle ii 6b, the mold 8 starts to be closed, a pressure air source device 1, namely, an air compressor or an air supply pump capable of generating pressure air, works to connect a pressure air supply pipeline with an air blowing total system 2, the air blowing total system 2 comprises an air blowing gas pipeline 21 and a control gas pipeline 22, an air filtering and pressure regulating device 211 is arranged on the air blowing gas pipeline 21, the air filtering and pressure regulating device 211 comprises an air filter 2111, a pressure reducing valve 2112 and an oil mist device 2113, the three components are sequentially arranged on the air blowing gas pipeline 21 from left to right in a position state shown in figure 1, a pressure regulating filtering and drying device 221 is arranged on the control gas pipeline 22, the pressure regulating filtering and drying device 221 comprises a pressure regulator 2211 and an air filter 2212, the two members are arranged in the positional state shown in fig. 1 in order from left to right, and a pressure indicator 222 is provided corresponding to, i.e., on the left side of the pressure regulator 2211, the cavity 81 of the mold 8 (i.e., the mold cavity) already mentioned above is also shown in fig. 1, a pressure indicator 222 for revealing the gas pressure adjusted by the pressure regulator 2211 is also shown on the left side of the pressure regulator 2211 in fig. 1, and the mold cooling water passage 82 formed in the mold 8 is also shown;

B) low-pressure blowing, wherein the blank, namely the blank, is pushed to the right position, low-pressure blowing is started, a second electromagnetic valve II 3b, a third electromagnetic valve III 3c and a fourth electromagnetic valve IV 3d which are connected with the control gas circuit 22 are electrified, a second angle seat valve II 422, a third angle seat valve III 511 and a fourth angle seat valve IV 521 form a passage, the other electromagnetic valves are in a power-off state, gas (namely low-pressure gas) passes through a low-pressure gas circuit 42 of a first distribution gas circuit I4, then passes through a second pressure regulating valve II 421 and a second angle seat valve II 422, is divided into a first blowing gas circuit I51 and a second blowing gas circuit II 52 of a second distribution gas circuit II 5, and is simultaneously blown into the mold 8 by a first blowing needle I6 a and a second blowing needle II 6b, and is switched to high-pressure blowing after the blowing timing is finished, and a second pressure indicating gauge II 423 which is arranged on the low-pressure gas circuit 42 and is positioned between the second pressure regulating valve II 421 and the second angle seat valve II 422 and is used for revealing the gas pressure regulated by the second pressure regulating;

C) high-pressure blowing, a first electromagnetic valve I3 a, a third electromagnetic valve III 3c and a fourth electromagnetic valve IV 3d which are connected with a control air path 22 are electrified, a first angle seat valve I412, a third angle seat valve III 511 and a fourth angle seat valve IV 521 become a passage, other electromagnetic valves are in a power-off state, air (namely the high-pressure air) passes through a high-pressure air path 41 of a first distribution air path I4, then passes through a first pressure regulating valve I411 and the first angle seat valve I412 to be divided into a first air blowing path I51 and a second air blowing path II 52, and is simultaneously blown into the mold 8 by a first air blowing needle I6 a and a second air blowing needle II 6b, the air blowing time is controlled to be 40-70s (adjusted in the range of 40s-70s according to different blow molding machines), the air blowing is stopped, the pressure is maintained at 0.6-0.8MPa for 10-20s, a pressure regulating valve I411 for revealing pressure after being adjusted by the first pressure regulating valve I411 is arranged on the high-pressure regulating valve 41 and is arranged between the first angle seat A first pressure indication table i 413 of the gas pressure;

D) and (C) deflating, after the pressure maintaining is finished, the first electromagnetic valve I3 a is electrified, the first angle seat valve I412 is switched on, the high-pressure air passage 41 becomes a normal passage, the fourth electromagnetic valve IV 3d and the fifth electromagnetic valve V3 e are electrified, the second air blowing passage II 52 becomes an air passage, the first air blowing passage I51 becomes an air bleeding passage, the fifth angle seat valve V512 is opened, the first silencer I7 a is switched on and begins to deflate, after a period of time, the fourth electromagnetic valve IV 3d and the fifth electromagnetic valve V3 e are closed, the third electromagnetic valve III 3C and the sixth electromagnetic valve VI 3f are opened, the sixth angle seat valve VI 522 is switched on, the first air blowing passage I51 becomes a normal passage, the second air blowing passage II 52 becomes an air bleeding passage, and the second silencer II 7b is switched on and begins to deflate.

In conclusion, the technical scheme provided by the invention overcomes the defects in the prior art, successfully completes the invention task and truly realizes the technical effects of the applicant in the technical effect column.