Control valve group and control loop for multi-station hydraulic blow molding device

Abstract

The utility model provides a control valve group. A multi-station hydraulic blow molding device comprises a left station group with at least one hydraulic blow molding machine and a right station group with at least one hydraulic blow molding machine, the control valve group comprises a main control servo valve, a left path control unit and a right path control unit, the left path control unit is used for controlling each hydraulic blow molding machine on the left station group, the right path control unit is used for controlling each hydraulic blow molding machine on the right station group, and each path control unit comprises a mold opening and closing servo valve and an auxiliary servo valve; the mold opening and closing servo valve is provided with a first oil inlet in fluid communication with the main control servo valve and a plurality of mold opening and closing action oil ports in fluid communication with the mold opening and closing action valve, and the first oil inlet is selectively communicated with the mold opening and closing action oil ports; the auxiliary servo valve is provided with a second oil inlet in fluid communication with the main control servo valve, a plurality of blowing nozzle action oil ports in fluid communication with the blowing nozzle action valve and a plurality of lifting action oil ports in fluid communication with the lifting action valve, and the second oil inlet is selectively communicated with the blowing nozzle action oil ports and the lifting action oil ports.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic blow molding technology, and in particular to a control valve group and control circuit for a multi-station hydraulic blow molding device. Background Technology

[0002] The working principle of a hydraulic blow molding machine is to heat and melt plastic granules or powder through an extruder, and then extrude the molten material into a closed mold through a hydraulic system to form a hollow plastic product. During the blow molding process, the hydraulic system provides a molding medium with a certain pressure to ensure that the material is evenly distributed in the mold and maintains the desired shape after cooling.

[0003] A multi-station hydraulic blow molding unit is a blow molding device that can simultaneously perform at least two sets of hydraulic blow molding operations. The hydraulic blow molding operation is completed by several hydraulic blow molding machines mounted on it, with one hydraulic blow molding machine corresponding to one "station". This blow molding unit can achieve extremely high output in a short period of time and has good market prospects.

[0004] However, existing multi-station hydraulic blow molding systems still use independent control valves to control the operation of each hydraulic blow molding machine. When there are a large number of hydraulic blow molding machines, the control circuits used to connect each control valve become overly redundant and complex. Furthermore, this individual control method is not conducive to ensuring uniform operation of each hydraulic blow molding machine, hindering the rapid execution of processes such as material feeding and demolding. Utility Model Content

[0005] In view of the disadvantages of using separate control for the hydraulic blow molding machine in the multi-station hydraulic blow molding device, the purpose of this utility model is to provide a control valve group and control circuit for a multi-station hydraulic blow molding device.

[0006] To achieve the above objectives, this utility model provides the following first technical solution: a control valve group for a multi-station hydraulic blow molding device, wherein the multi-station hydraulic blow molding device includes a left station group with at least one hydraulic blow molding machine and a right station group with at least one hydraulic blow molding machine, wherein the hydraulic blow molding machine has a mold opening and closing action valve, a nozzle action valve, and a lifting action valve, and the control valve group includes a main control servo valve, a left-path control unit for controlling each hydraulic blow molding machine in the left station group, and a right-path control unit for controlling each hydraulic blow molding machine in the right station group, wherein the left-path control unit and the right-path control unit are connected. Each control unit includes a mold-opening / closing servo valve and an auxiliary servo valve. The mold-opening / closing servo valve has a first oil inlet fluidly connected to the main control servo valve and a plurality of mold-opening / closing action oil ports fluidly connected to the mold-opening / closing action valve. The first oil inlet can selectively connect to the mold-opening / closing action oil ports. The auxiliary servo valve has a second oil inlet fluidly connected to the main control servo valve, a plurality of nozzle action oil ports fluidly connected to the nozzle action valve, and a plurality of lifting action oil ports fluidly connected to the lifting action valve. The second oil inlet can selectively connect to the nozzle action oil ports and the lifting action oil ports.

[0007] In the first technical solution described above, preferably, the mold opening and closing servo valve further includes a first return port fluidly connected to the main control servo valve, and the auxiliary servo valve further includes a second return port fluidly connected to the main control servo valve. More preferably, the main control servo valve includes at least one main inlet, a mold opening and closing control port fluidly connected to the first inlet, an auxiliary control port fluidly connected to the second inlet, and a main return port. The at least one main inlet can selectively fluidly connect to the mold opening and closing control port and the auxiliary control port, and both the first return port and the second return port are fluidly connected to the main return port.

[0008] In the first technical solution described above, preferably, the hydraulic blow molding machine further includes a sub-mold action valve, the auxiliary control servo valve further includes a sub-mold action oil port fluidly connected to the sub-mold action valve, and the second oil inlet can selectively fluidly connect to the sub-mold action oil port.

[0009] In addition, the present invention also provides the following second technical solution: a control circuit having a control valve group as described in any of the first technical solution and its preferred solutions, and further including an oil tank and at least one oil pump, wherein the at least one oil pump, the at least one main oil inlet, the main oil return port and the oil tank are sequentially fluidly connected to form a circuit for the circulation of hydraulic oil.

[0010] In the second technical solution described above, preferably, the at least one oil pump includes a mold-opening / closing oil pump and an auxiliary oil pump. The at least one main oil inlet includes a mold-opening / closing main oil inlet fluidly connected to the mold-opening / closing oil pump and an auxiliary main oil inlet fluidly connected to the auxiliary oil pump. The mold-opening / closing main oil inlet and the auxiliary main oil inlet are independent of each other. The mold-opening / closing main oil inlet can be selectively connected to the mold-opening / closing control oil port, and the auxiliary main oil inlet can be selectively fluidly connected to the auxiliary control oil port. Further preferably, the rated output pressure of the mold-opening / closing oil pump is greater than the rated output pressure of the auxiliary oil pump.

[0011] Compared to existing technologies, the control valve assembly provided by this invention can control the flow of hydraulic oil in and out of the left and right control units via a main control servo valve, enabling the start-up and shutdown of all hydraulic blow molding machines in any workstation group. The left and right control units can respectively control all hydraulic blow molding machines in their respective workstation groups to perform unified actions. This control valve assembly effectively reduces the complexity of the control circuit and standardizes the action time of the hydraulic blow molding machines, facilitating rapid processes such as material feeding and demolding. Attached Figure Description

[0012] Figure 1 A simplified structural diagram of the hydraulic blow molding machine provided by this utility model;

[0013] Figure 2 A simplified illustration of the initial stage of blow molding operation provided by this utility model;

[0014] Figure 3 A simplified illustration of the final stage of the blow molding process provided by this utility model;

[0015] Figure 4 A perspective view of the control valve assembly provided for this utility model;

[0016] Figure 5 for Figure 4 A 3D view of the master servo valve of the control valve group shown.

[0017] Figure 6 for Figure 4 A 3D view of the servo valve for opening and closing the control valve assembly shown.

[0018] Figure 7 for Figure 4 A 3D view of the auxiliary servo valve of the control valve assembly shown.

[0019] Figure 8 This is a schematic diagram of the control circuit provided by this utility model; however, the return oil routes between the control valve group and each actuating valve are not shown.

[0020] The image is labeled as follows:

[0021] 10. Hydraulic blow molding machine; 20. Precast parts; 30. Main control servo valve; 40. Mold opening and closing servo valve; 50. Auxiliary servo valve; 60. Oil tank; 70. Mold opening and closing oil pump; 80. Auxiliary oil pump;

[0022] 11. Base; 12. First template; 13. Second template; 14. First module; 15. Second module; 16. Mold opening / closing valve; 17. Nozzle; 18. Sealing pin; 191. Lifting valve; 192. Nozzle valve; 193. Sub-mold valve;

[0023] 31. Main oil inlet; 32. Main oil return outlet; 33. Mold opening / closing control oil inlet; 34. Auxiliary control oil inlet; 35. Sub-oil return outlet; 36. Mold opening / closing main oil inlet; 47. Auxiliary main oil inlet;

[0024] 41. First oil inlet; 42. Oil inlet for mold opening and closing; 43. First oil return outlet;

[0025] 51. Second oil inlet; 52. Lifting / lowering oil inlet; 53. Nozzle oil inlet; 54. Second oil return outlet; 55. Sub-mold oil inlet;

[0026] A. Mold cavity. Detailed Implementation

[0027] To explain in detail the technical content, structural features, achieved objectives and effects of this application, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings.

[0028] In this application, spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side” (e.g., as in a “sidewall”) are used to describe the relationship between one element and another element as shown in the accompanying drawings. Spatial relative terms are intended to include different orientations of the device in use, operation, and / or manufacture other than those depicted in the drawings. For example, if the device in the drawings is flipped, an element described as “below” or “under” another element or feature would then be positioned “above” said other element or feature. Thus, the exemplary term “below” can include both above and below orientations. Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or in other orientations), thus interpreting the spatial relative descriptive terms used herein accordingly.

[0029] This invention provides a control valve assembly that can be used in a continuous multi-station hydraulic blow molding device. The continuous multi-station hydraulic blow molding device includes a left station group with at least one hydraulic blow molding machine and a right station group with at least one hydraulic blow molding machine. To facilitate the introduction of the control valve assembly provided by this invention, the hydraulic blow molding machine will be briefly described below.

[0030] Figure 1 A simplified structure of a hydraulic blow molding machine 10 is shown, comprising a base 11, a first template 12 slidably mounted on the base 11, a second template 13 slidably mounted on the base 11, and a blow molding die. The blow molding die includes a first module 14 and a second module 15 capable of mold opening and closing operations. The first and second molds are respectively fixed to the first and second templates and can be moved by the first and second templates. The hydraulic blow molding machine 10 has a closed state where the first and second templates are close together to allow the first and second modules to close, and a parting state where the first and second templates are far apart to allow the first and second modules to separate.

[0031] Understandably, the hydraulic blow molding machine 10 can perform mold opening and closing operations by controlling the movement of the first and second mold plates. The mold opening and closing operations of the hydraulic blow molding machine 10 of this application are controlled by a hydraulic control system, specifically the mold opening and closing action valve 16 (see...) configured on the hydraulic blow molding machine 10. Figure 8 By selectively inputting hydraulic oil into the inlet of the mold opening and closing valve 16, the corresponding valve can be activated, thereby causing the driving oil to move the first and second modules in opposite directions. This technology is existing technology and will not be described in detail here.

[0032] Combination Figure 2-3 This illustrates the basic process of hydraulic blow molding. Specifically, both the first and second modules have an inner surface (not shown) that mates to define the mold cavity A into the desired container shape. The upper part of the blow molding die is configured to receive and hold the preform 20 (i.e., the blank with a preliminary shape). The hydraulic blow molding machine 10 also includes a nozzle 17 for suspending the preform 20 and a sealing pin 18 for selectively sealing the nozzle 17.

[0033] Before the preform 20 is placed in the mold cavity A, the preform 20 is heated to a temperature suitable for the molten state; then, the preform 20 is placed into the mold cavity A of the blow molding mold; finally, the sealing pin 18 is raised, the nozzle 17 is opened, and the molding medium is sprayed from the nozzle 17 into the preform 20 and extrudes the preform into a shape that fits the inner surface of the mold cavity A.

[0034] In the above process, the lifting and lowering action of the sealing pin 18 and the injection action of the blow molding medium are both controlled by the corresponding lifting and lowering valve 191 (see...). Figure 8 ) and mouthpiece actuation valve 192 (see Figure 8Direct control. As mentioned above, this is existing technology and will not be elaborated further here.

[0035] Back Figure 4 This invention illustrates a control valve assembly provided by the present invention, which is used to control the blow molding operations of each hydraulic blow molding machine 10 on a continuous multi-station hydraulic blow molding device. Specifically, the control valve assembly includes a main control servo valve 30 for controlling the inflow and outflow of hydraulic oil, a left-side control unit for controlling each hydraulic blow molding machine 10 on the left-side group, and a right-side control unit for controlling each hydraulic blow molding machine 10 on the right-side group. Both the left-side and right-side control units include a mold-opening servo valve 40 for controlling the mold-opening and closing actions of the hydraulic blow molding machines, and an auxiliary servo valve 50 for controlling the lifting and spraying actions of the hydraulic blow molding machines.

[0036] Since the oil circuits, upstream and downstream equipment, and components and structures of the left and right station control units in the control valve assembly of this application are basically the same, for ease of explanation, when it is necessary to distinguish between the left and right station control units, "A" (or "B") will be added to the end of the labeled number to indicate that the oil circuit, upstream and downstream equipment, or component is associated with the left (or right) station control unit; if the labeled number does not have a letter suffix, it indicates that the left and right control units share this characteristic (but does not indicate that the left and right control units are associated with the same oil circuit, have upstream or downstream equipment, or use the same component).

[0037] The main control valve 30 is used to control the oil inlet and outlet of the left control unit / right control unit, thereby controlling the start or stop of all hydraulic blow molding machines 10 on the left / right workstation group. Specifically, in conjunction with Figure 5 The main control valve 30 has at least one main inlet 31 for hydraulic oil to flow in, a main return port 32 for hydraulic oil to flow out, a mold opening and closing control port 33A for outputting hydraulic oil to the mold opening and closing servo valve 40A on the left work station control unit, a mold opening and closing control port 33B for outputting hydraulic oil to the mold opening and closing servo valve 40B on the right work station control unit, an auxiliary control port 34A for outputting hydraulic oil to the auxiliary servo valve 50A on the left work station control unit, an auxiliary control port 34B for outputting hydraulic oil to the auxiliary servo valve 50B on the right work station control unit, a sub-return port 35A for receiving return oil from the left control unit, and a sub-return port 35B for receiving return oil from the right control unit.

[0038] The aforementioned sub-return ports 35A and 35B are both fluidly connected to the main return port 32. At least one of the aforementioned main inlet ports 31 can selectively connect to the mold opening / closing control ports 33A and 33B, as well as the auxiliary control ports 34A and 34B. In this application, "selectively fluidly connected" means selectively connecting or disconnecting the fluid paths of the two ports and controlling the hydraulic oil flow rate on the fluid paths of the two ports. The servo valve can adjust the opening degree of its internal valves based on the input electromagnetic signal to selectively open or disconnect the fluid path or change the hydraulic oil flow rate on the corresponding fluid path; this part is prior art and will not be elaborated here.

[0039] See Figure 6 and Figure 8 The mold-opening servo valve 40 has a first inlet 41 that is fluidly connected to the mold-opening control port 33, a plurality of mold-opening action ports 42 that are fluidly connected to the mold-opening action valves 16 of all hydraulic blow molding machines 10 in the corresponding workstation group, and a first return port 43 that can accept the return oil from the mold-opening action valves 16 and is fluidly connected to the sub-return port 35. The first inlet 41 can selectively be fluidly connected to the mold-opening action ports 42 to control all hydraulic blow molding machines 10 in the corresponding workstation group to perform mold-opening actions simultaneously.

[0040] See Figure 7 and Figure 8 The auxiliary servo valve 50 has a second inlet 51 that is fluidly connected to the auxiliary control port 34, a lifting action port 52 that is fluidly connected to the lifting action valves 191 of all hydraulic blow molding machines 10 in the corresponding workstation group, a nozzle action port 53 that is fluidly connected to the nozzle action valves 192 of all hydraulic blow molding machines 10 in the corresponding workstation group, and a second return port 54 that can accept the return oil from the lifting action valves 191 and the nozzle action valves 192 and is fluidly connected to the sub-return port 35. The second inlet 51 can selectively fluidly connect to the lifting action valves 191 and the nozzle action valves 192 to control all hydraulic blow molding machines 10 in the corresponding workstation group to simultaneously perform lifting and spraying actions.

[0041] Furthermore, the hydraulic blow molding machine 10 also includes a sub-mold (not shown) and a sub-mold actuation valve 193 for controlling the sub-mold. The sub-mold is a component used to be placed inside the mold cavity A of the blow molding die and to form the inner surface of the blow-molded product; it is also called a core or rear mold. This part is prior art and will not be described in detail. The auxiliary servo valve 50 also includes a sub-mold actuation port 55 that is fluidly connected to the sub-mold actuation valve 193. The second inlet port 51 can selectively fluidly connect to the sub-mold actuation port 55 to control all hydraulic blow molding machines 10 on the workstation group to simultaneously perform sub-mold actuation.

[0042] Figure 8The control circuit provided by this invention is shown. The control circuit has the control valve group and its corresponding actuating valve as described above. In addition, the control circuit also includes an oil tank 60 and at least one oil pump. The at least one oil pump, the main oil inlet 31, the main oil return port 32 and the oil tank 60 are sequentially fluidly connected to form a circuit for the circulation of hydraulic oil.

[0043] Furthermore, considering that the hydraulic pressure required by the mold-opening / closing actuation valve 16 is generally larger, while the hydraulic pressure required by auxiliary actuation valves such as the lifting actuation valve 191 is smaller, the at least one oil pump provided in this embodiment includes a mold-opening / closing oil pump 70 and an auxiliary oil pump 80 with a rated output pressure lower than that of the mold-opening / closing oil pump 70. At least one main oil inlet 31 on the main control servo valve 30 can be divided into a mold-opening / closing main oil inlet 36 and an auxiliary main oil inlet 37, which are independent of each other (meaning that inside the main control servo valve 30, the mold-opening / closing main oil inlet 36 and the auxiliary main oil inlet 37 cannot be fluidly connected). The mold-opening / closing oil pump 70 is fluidly connected to the mold-opening / closing main oil inlet 36, which can selectively be fluidly connected to the mold-opening control oil port 33; the auxiliary mold oil pump 80 is fluidly connected to the auxiliary main oil inlet 37, which can selectively be fluidly connected to the auxiliary control oil port 34. This configuration allows for the use of an auxiliary oil pump with a lower rated output pressure (i.e., lower cost) and improves the overall energy efficiency of the multi-station hydraulic blow molding unit. Understandably, in this configuration, the left and right station groups of the multi-station hydraulic blow molding unit will alternately perform mold opening and closing actions and auxiliary actions (including lifting actions, nozzle actions, and sub-mold actions).

[0044] The above embodiments are only for illustrating the technical concept and features of this application, and are intended to enable those skilled in the art to understand the content of this application and implement it accordingly. They should not be construed as limiting the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit of this application should be included within the scope of protection of this application.

Claims

1. A control valve group for a multi-station hydraulic blow molding device, the multi-station hydraulic blow molding device comprising a left station group having at least one hydraulic blow molding machine and a right station group having at least one hydraulic blow molding machine, wherein the hydraulic blow molding machine has a mold opening / closing valve, a nozzle valve, and a lifting valve, characterized in that, The control valve group includes a main control servo valve, a left-path control unit for controlling each hydraulic blow molding machine on the left workstation group, and a right-path control unit for controlling each hydraulic blow molding machine on the right workstation group. Both the left-path control unit and the right-path control unit include a mold-opening / closing servo valve and an auxiliary servo valve. The mold-opening / closing servo valve has a first oil inlet fluidly connected to the main control servo valve and several mold-opening / closing actuation ports fluidly connected to the mold-opening / closing actuation valve. The first oil inlet can selectively connect to the mold-opening / closing actuation ports. The auxiliary servo valve has a second oil inlet fluidly connected to the main control servo valve, several nozzle actuation ports fluidly connected to the nozzle actuation valve, and several lifting actuation ports fluidly connected to the lifting actuation valve. The second oil inlet can selectively connect to the nozzle actuation ports and the lifting actuation ports.

2. The control valve assembly according to claim 1, characterized in that, The mold opening and closing servo valve further includes a first return port that is fluidly connected to the main control servo valve, and the auxiliary servo valve further includes a second return port that is fluidly connected to the main control servo valve.

3. The control valve assembly according to claim 2, characterized in that, The main control servo valve includes at least one main oil inlet, a mold opening / closing control oil inlet fluidly connected to the first oil inlet, an auxiliary control oil inlet fluidly connected to the second oil inlet, and a main return oil inlet. The at least one main oil inlet can selectively be fluidly connected to the mold opening / closing control oil inlet and the auxiliary control oil inlet. The first return oil inlet and the second return oil inlet are both fluidly connected to the main return oil inlet.

4. The control valve assembly according to claim 1, characterized in that, The hydraulic blow molding machine further includes a sub-mold action valve, and the auxiliary control servo valve further includes a sub-mold action oil port that is fluidly connected to the sub-mold action valve. The second oil inlet can selectively be fluidly connected to the sub-mold action oil port.

5. A control circuit comprising a control valve assembly as described in any one of claims 1-4, characterized in that, It also includes an oil tank and at least one oil pump, wherein the at least one oil pump, the at least one main oil inlet, the main oil return port and the oil tank are sequentially fluidly connected to form a circuit for the circulation of hydraulic oil.

6. The control loop according to claim 5, characterized in that, The at least one oil pump includes a mold-opening and closing oil pump and an auxiliary oil pump. The at least one main oil inlet includes a mold-opening and closing main oil inlet fluidly connected to the mold-opening and closing oil pump and an auxiliary main oil inlet fluidly connected to the auxiliary oil pump. The mold-opening and closing main oil inlet and the auxiliary main oil inlet are independent of each other. The mold-opening and closing main oil inlet can be selectively connected to the mold-opening and closing control oil port, and the auxiliary main oil inlet can be selectively fluidly connected to the auxiliary control oil port.

7. The control loop according to claim 6, characterized in that, The rated output pressure of the mold-opening oil pump is greater than the rated output pressure of the auxiliary oil pump.

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