An electric adjustment device for die gap of a blow molding machine

Abstract

The invention discloses an electric adjustment device for the gap between the die and the blow molding machine, comprising a servo reduction motor, a box, an eccentric shaft, a connecting plate, a pin and an intermediate pull rod, wherein the eccentric shaft is located in the box and placed at the lower part of the box, the servo reduction motor is placed outside the box and its rotating shaft is connected to one end of the eccentric shaft by transmission, the pin is located in the box and placed above the eccentric shaft, two upper and lower opposite shaft holes are opened on the connecting plate, the pin and the eccentric shaft pass through the shaft holes at the upper and lower parts respectively, the intermediate pull rod is installed in the box in a vertical direction and its upper and lower ends extend out of the box, the intermediate pull rod is provided with an upper opening and a lower opening, and the diameter of the lower opening is larger than the diameter of the eccentric shaft. The electric adjustment device avoids the direct connection between the eccentric shaft and the intermediate pull rod, the intermediate pull rod will not shake when in motion, the number of needle roller bearings installed is reduced, the cost is saved, and the practicability is high.

Description

Technical Field

[0001] The invention relates to an electric die gap adjustment device for a blow molding machine, and relates to the technical field of blow molding machinery. Background Art

[0002] Blow molding, also known as hollow blow molding, is a rapidly developing plastic processing method. The tubular plastic preform obtained by extrusion or injection molding of thermoplastic resin is placed in a split mold while hot (or heated to a softened state). After the mold is closed, compressed air is immediately introduced into the preform to inflate the plastic preform and cling to the inner wall of the mold. After cooling and demolding, various hollow products are obtained. The mold mouth of the blow molding machine is also commonly called the mouth mold or the die head mouth mold. The melt between the inner wall of the mold sleeve and the outer wall of the mold core can be changed by adjusting the lifting and lowering of the mold sleeve of the mouth mold structure system.

[0003] The width of the gap of the outlet of the flow channel (i.e. the width of the gap of the die opening) can change the wall thickness of the molten plastic preform as needed and finally make the wall thickness of the blown hollow plastic product meet the process requirements, because the wall thickness of hollow plastic containers with different uses and specifications is different. In particular, during the plastic preform molding process, the gap of the outlet of the melt flow channel is also adjusted as needed to control the wall thickness distribution of the preform and obtain a hollow plastic product with a relatively uniform wall thickness distribution. The Chinese invention patent authorization announcement number CN106827463A is an electric adjustment device for the die gap of a blow molding machine. The simplified structure makes it easy to manufacture and assemble, and is convenient for daily use and maintenance, and is beneficial to improving the response speed, avoiding time lag, and is beneficial to reducing energy consumption and ensuring ideal output torque, and ensuring the adjustment accuracy of the die gap. However, the eccentric shaft inside it is directly connected to the middle tie rod, which makes the middle tie rod easy to shake, causing friction between the middle tie rod and the box. In order to solve the above problems, many specific needle roller bearings are manufactured and assembled in the patent to reduce this shaking, and these needle roller bearings have high requirements on processing accuracy, long production cycle and high cost. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an electric mold gap adjustment device for a blow molding machine which has a simple structure and can effectively ensure the gap adjustment accuracy and save the manufacturing cost.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] A blow molding machine die gap electric adjustment device comprises a servo reduction motor, a box, an eccentric shaft, a connecting plate, a pin shaft and an intermediate pull rod, wherein the eccentric shaft is located in the box body and is placed at the lower part of the box body, and a pair of rotating shaft holes for the two ends of the eccentric shaft to pass through are opened on the left and right side plates of the box body, the servo reduction motor is placed outside the box body and its rotating shaft is transmission-connected with one end of the eccentric shaft, the pin shaft is located in the box body and is placed above the eccentric shaft, and two upper and lower opposite shaft holes are opened on the connecting plate, which are an upper shaft hole and a lower shaft hole, and the pin shaft passes through the upper shaft hole And it is connected to the connecting plate, the shaft body of the eccentric shaft passes through the lower shaft hole and is connected to the connecting plate, the intermediate pull rod is installed in the box body and lifted in the vertical direction, and its upper and lower ends extend out of the box body, an upper opening hole is provided in the middle of the upper rod body of the intermediate pull rod for the pin shaft to pass through, the pin shaft passes through the upper opening hole and is connected to the upper rod body of the intermediate pull rod, the lower rod body of the intermediate pull rod is provided with a lower opening hole for the middle shaft rod of the eccentric shaft to pass through, the diameter of the lower opening hole is larger than the diameter of the eccentric shaft, when the eccentric shaft rotates, there is no contact between its shaft rod and the inner hole wall of the lower opening.

[0007] Preferably, a lower bearing is fixed between the eccentric shaft and the lower shaft hole of the connecting plate.

[0008] Preferably, an upper bearing is fixed between the pin shaft and the upper shaft hole of the connecting plate.

[0009] Preferably, the upper bearing adopts a cylindrical roller bearing, and the lower bearing adopts a needle roller bearing.

[0010] Preferably, there are two connecting plates, which are symmetrically arranged on both sides of the middle pull rod.

[0011] Preferably, deep groove ball bearings are provided between the two ends of the eccentric shaft and the rotating shaft hole of the box body.

[0012] Preferably, the box body includes a middle shell and an upper end cover and a lower end cover. The middle shell is open at the top and bottom. The upper end cover and the lower end cover are respectively detachably fixedly connected to the upper and lower openings of the middle shell. The upper and lower ends of the intermediate pull rod respectively pass through the middle of the upper end cover and the lower end cover and can telescope up and down relatively freely.

[0013] Preferably, a retaining ring is provided between the upper shaft hole of the connecting plate and the pin shaft, and the retaining ring is located outside the upper bearing and arranged in parallel with the upper bearing.

[0014] Preferably, the intermediate pull rod includes a pull rod body and an upper guide column and a lower guide column respectively arranged at the upper and lower ends of the pull rod body, the upper guide column, the lower guide column and the pull rod body are integrally formed, the upper guide column and the lower guide column respectively pass through the upper and lower parts of the box body, and the upper opening and the lower opening are respectively arranged on the pull rod body in the up and down directions.

[0015] Preferably, the shaft holes of the left and right side plates on the box body are respectively covered with bearing covers, and the reduction box of the servo motor is fixedly connected to the bearing cover on the same side thereof by screws.

[0016] Compared with the prior art, the advantages of the present invention are: the electric mold gap adjustment device of the blow molding machine of the present invention has a simple structure and is easy to install and manufacture. By setting a connecting plate to connect the bearing and the eccentric shaft, the eccentric shaft drives the connecting plate to move, and then the connecting plate drives the middle pull rod to move up and down, thereby avoiding the direct connection between the eccentric shaft and the middle pull rod, avoiding the shaking of the middle pull rod caused by the direct connection between the eccentric shaft and the middle pull rod in the prior art, and reducing the number of needle bearings installed, saving costs, and effectively ensuring the accuracy of gap adjustment, with high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a side sectional view of the present invention;

[0019] Figure 2 This is an axonometric view of the present invention when the middle housing and the servo reduction motor are not installed;

[0020] Figure 3 This is an axonometric view of the present invention when the middle housing and the servo reduction motor are not installed and only one connecting plate is installed;

[0021] Figure 4 This is an axonometric view of the present invention when the servo reduction motor is not installed;

[0022] Figure 5 is a front view of the intermediate pull rod of the present invention;

[0023] Figure 6 It is a front view of the connecting plate of the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention:

[0025] like Figures 1 to 4The die gap electric adjustment device of a blow molding machine shown in the figure comprises a servo reduction motor 1, a box body, an eccentric shaft 2, a connecting plate 3, a pin shaft 4 and an intermediate pull rod. The eccentric shaft 2 is located in the box body and is placed at the lower part of the box body. A pair of rotating shaft holes for the two ends of the eccentric shaft 2 to pass through are provided on the left and right side plates of the box body. In this embodiment, in order to facilitate installation, disassembly and later maintenance, the box body comprises a middle shell body 5 and an upper end cover 6 and a lower end cover 7. A linear displacement sensor 21 fixed by a bracket 20 is provided on the upper part of the upper end cover 6. The middle shell body 5 is opened at the top and bottom, and the upper end cover 6 and the lower end cover 7 are respectively detachable fixed It is fixedly connected to the openings at the upper and lower parts of the middle shell 5, and the shaft holes are arranged on both sides of the lower part of the middle shell 5. In order to improve the rotation stability of the eccentric shaft 2, deep groove ball bearings 8 are arranged between the two ends of the eccentric shaft 2 and the shaft holes of the box body. The servo reduction motor 1 is placed outside the box body and its shaft is transmission connected to one end of the eccentric shaft 2, and then the servo reduction motor 1 drives the eccentric shaft 2 to rotate eccentrically. The shaft holes of the left and right side plates on the box body are respectively covered with bearing covers 22. The reduction box of the servo motor is fixedly connected to the bearing cover 22 on the same side thereof by screws. The servo motor here is a servo motor with forward and reverse rotation functions.

[0026] The pin shaft 4 is located in the upper part of the middle shell 5 and is placed above the eccentric shaft 2. The two ends of the pin shaft 4 are not connected to the inner wall of the middle shell 5, but can move freely up and down relative to the middle shell 5. Figure 6As shown, the connecting plate 3 is provided with two upper and lower opposite axial holes, namely an upper axial hole 9 and a lower axial hole 10. The pin shaft 4 passes through the upper axial hole 9 and is connected to the connecting plate 3. The pin shaft 4 rotates freely relative to the connecting plate 3, and then the up and down movement of the connecting plate 3 can also drive the up and down movement of the pin shaft 4. The shaft body of the eccentric shaft 2 passes through the lower axial hole 10 at the lower part and is connected to the connecting plate 3. The eccentric shaft 2 rotates freely relative to the connecting plate 3. Therefore, when the eccentric shaft 2 rotates, it can drive the up and down movement of the connecting plate 3, and then further drive the up and down movement of the pin shaft 4. The intermediate pull rod is installed in the box body along the vertical direction and its upper and lower ends extend out of the box body. In this embodiment, the upper and lower ends of the intermediate pull rod pass through the upper end covers 6 and the lower end cover 7 of the upper and lower parts respectively. The middle part of the upper rod body of the intermediate pull rod is provided with an upper opening 11 for the pin shaft 4 to pass through. 4 passes through the upper opening 11 and is connected to the upper rod body of the intermediate rod. In actual application, the rod body of the intermediate rod is movably connected to the pin shaft 4, and the pin shaft 4 can rotate freely relative to the intermediate rod. The lower rod body of the intermediate rod is provided with a lower opening 12 for the middle shaft rod of the eccentric shaft 2 to pass through. The lower opening 12 is a waist-shaped hole, and its diameter is larger than the diameter of the eccentric shaft 2. When the eccentric shaft 2 rotates, there is no contact between its shaft rod and the inner hole wall of the lower opening 12. Therefore, when the eccentric shaft 2 rotates, it will not touch the intermediate rod, nor will it have corresponding interference with the intermediate rod, thereby ensuring that the eccentric shaft 2 can rotate eccentrically normally. In this embodiment, the number of the connecting plates 3 is two and they are symmetrically arranged on both sides of the intermediate rod, thereby further effectively ensuring the stability of the operation of the overall mechanism. In addition, in actual application, in order to improve stability, such as Figure 5 As shown, the intermediate tie rod includes a tie rod body 15 and an upper guide column 13 and a lower guide column 14 respectively arranged at the upper and lower ends of the tie rod body 15. The upper guide column 13, the lower guide column 14 and the tie rod body 15 are integrally formed. The upper guide column 13 and the lower guide column 14 pass through the upper and lower parts of the box body respectively. The upper opening 11 and the lower opening 12 are respectively arranged on the tie rod body 15 in the upper and lower directions, thereby effectively improving the stability of the intermediate tie rod during vibration, and facilitating the opening of the shaft hole, facilitating production, and having high practicality.

[0027] In this embodiment, in order to improve the rotational stability of the eccentric shaft 2 relative to the connecting plate 3, a lower bearing 16 is fixed between the eccentric shaft 2 and the lower shaft hole of the connecting plate 3. Further, in order to improve the rotational stability of the pin shaft 4 relative to the connecting plate 3, an upper bearing 17 is fixed between the pin shaft 4 and the upper shaft hole of the connecting plate 3. In this embodiment, the upper bearing 17 adopts a cylindrical roller bearing, and the lower bearing 16 adopts a needle bearing, thereby further improving the relative rotational stability of the corresponding components.

[0028] In this embodiment, in order to avoid the relative stability between the upper bearing 17 and the pin 4, a retaining ring 19 is provided between the upper shaft hole of the connecting plate 3 and the pin 4. The retaining ring 19 is located outside the upper bearing 17 and arranged in parallel with the upper bearing 17.

[0029] In practical applications, the servo reduction motor 1 first drives the eccentric shaft 2 to rotate. During the eccentric rotation of the eccentric shaft 2, the two connecting plates 3 will be driven to vibrate up and down. Since the upper part of the connecting plate 3 is connected to the pin shaft 4, the pin shaft 4 will also be driven to rotate. Since the middle part of the pin shaft 4 is movably connected to the middle tie rod, when the pin shaft 4 vibrates up and down, the middle tie rod will also be driven to move up and down. According to the prior art, in practical applications, the lower guide post at the lower end of the middle tie rod is connected to the guide post connecting seat in the die device of the die head mechanism of the blow molding machine, so that the lower guide post moves up and down. When the guide column connecting seat is moved up and down, the corresponding connecting parts will be further used to drive the die gap adjustment block on the die device to move up and down, thereby realizing the die gap adjustment process. A cam slider mechanism is formed between the middle pull rod, the pin shaft 4, the connecting rod and the eccentric shaft 2. The up and down telescopic movement of the middle pull rod is realized through the rotation of the eccentric shaft 2, thereby avoiding the direct connection between the eccentric shaft 2 and the middle pull rod, avoiding the shaking of the middle pull rod, and reducing the number of needle bearings installed compared with the prior art, saving costs, effectively ensuring the gap adjustment accuracy, and having high practicality.

[0030] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An electric adjustment device for the die gap of a blow molding machine, characterized in that: It includes a servo reduction motor, a box body, an eccentric shaft, a connecting plate, a pin shaft and an intermediate pull rod, the eccentric shaft is located in the box body and placed at the lower part of the box body, a pair of rotating shaft holes for the two ends of the eccentric shaft to pass through are opened on the left and right side plates of the box body, the servo reduction motor is placed outside the box body and its rotating shaft is transmission connected with one end of the eccentric shaft, the pin shaft is located in the box body and placed above the eccentric shaft, two upper and lower opposite shaft holes are opened on the connecting plate, respectively, the upper shaft hole and the lower shaft hole, the pin shaft passes through the upper shaft hole and is connected to the connecting plate, the shaft body of the eccentric shaft passes through the lower shaft hole and is connected to the connecting plate, the intermediate pull rod is installed in the box body for lifting and lowering in the vertical direction, and its upper and lower ends extend out of the box body, an upper opening hole for the pin shaft to pass through is provided in the middle of the upper rod body of the intermediate pull rod, the pin shaft passes through the upper opening hole and is connected to the upper rod body of the intermediate pull rod, and the lower rod body of the intermediate pull rod is provided with A lower opening for the middle shaft of the eccentric shaft to pass through, the diameter of the lower opening is larger than the diameter of the eccentric shaft, when the eccentric shaft rotates, there is no contact between its shaft and the inner hole wall of the lower opening, the number of the connecting plates is two and they are symmetrically arranged on both sides of the middle pull rod, the box body includes a middle shell body and an upper end cover and a lower end cover, the middle shell body is open at the top and bottom, the upper end cover and the lower end cover are respectively detachably fixedly connected to the openings of the upper and lower parts of the middle shell body, the upper and lower ends of the middle pull rod respectively pass through the middle of the upper end cover and the lower end cover and can telescope up and down relatively freely, the middle pull rod includes a pull rod body and an upper guide column and a lower guide column respectively arranged at the upper and lower ends of the pull rod body, the upper guide column, the lower guide column and the pull rod body are integrally formed, the upper guide column and the lower guide column respectively pass through the upper and lower parts of the box body, and the upper opening and the lower opening are respectively arranged on the pull rod body in the up and down directions.

2. The electric adjustment device for the die gap of a blow molding machine according to claim 1, characterized in that: A lower bearing is fixed between the eccentric shaft and the lower shaft hole of the connecting plate.

3. The electric adjustment device for the die gap of a blow molding machine according to claim 2, characterized in that: An upper bearing is fixed between the pin shaft and the upper shaft hole of the connecting plate.

4. The electric adjustment device for the die gap of a blow molding machine according to claim 3, characterized in that: The upper bearing adopts a cylindrical roller bearing, and the lower bearing adopts a needle roller bearing.

5. The electric adjustment device for the die gap of a blow molding machine according to claim 1, characterized in that: Deep groove ball bearings are arranged between the two ends of the eccentric shaft and the rotating shaft hole of the box body.

6. The electric die gap adjustment device for a blow molding machine according to claim 3 or 4, characterized in that: A retaining ring is arranged between the upper shaft hole of the connecting plate and the pin shaft. The retaining ring is located outside the upper bearing and arranged in parallel with the upper bearing.

7. The electric adjustment device for the die gap of a blow molding machine according to claim 1, characterized in that: The rotating shaft holes of the left and right side plates on the box body are respectively covered with bearing covers, and the reduction box of the servo motor is fixedly connected with the bearing cover on the same side thereof by screws.

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