Rotary valve type closed nozzle and material pipe

Abstract

The invention belongs to the technical field of injection molding machines, and particularly relates to a rotary valve type closed nozzle and a material pipe. Comprising a transition nozzle, a valve element assembly and a positioning oil cylinder, the positioning oil cylinder is arranged on the transition nozzle, an injection runner and a valve element channel are formed in the transition nozzle and perpendicularly intersect, one end of the valve element assembly is rotationally arranged in the valve element channel, and the other end of the valve element assembly is rotationally arranged in the valve element channel. The positioning oil cylinder drives the valve element assembly to rotate so as to open or close the injection runner; the valve element assembly comprises a top gland, a rotary valve element, a bottom gland and a rotary shaft element, the top gland is detachably installed on the top of the valve element channel, the rotary valve element is rotationally arranged in the valve element channel and rotationally connected with the top gland, and one end of the rotary shaft element extends out of the transition nozzle and is in transmission connection with the positioning oil cylinder. The bottom gland abuts against a shaft shoulder of the rotating shaft core and is detachably connected with the bottom of the valve element channel, and the rotating shaft core is in transmission connection with the positioning oil cylinder. Maintenance and overhaul are simple, and cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding machines, and in particular relates to a rotary valve type closed nozzle and a material pipe. Background Art

[0002] The injection molding machine is the main molding equipment that uses plastic molding molds to make plastic products of various shapes from thermoplastics or thermosetting plastics. The injection molding machine can heat the plastic and apply high pressure to the molten plastic to make it ejected and fill the mold cavity. The working principle of the injection molding machine is similar to that of a syringe for injection. It uses the thrust of the screw (or plunger) to squeeze the molten plastic from the nozzle through the material pipe, inject the plasticized molten state (i.e. viscous flow state) plastic into the closed mold cavity, and obtain the product after solidification and finalization. In order to avoid the molten plastic from flowing out when the machine is stopped after the injection molding is completed, a switch needs to be set in the nozzle to close the flow channel.

[0003] In the traditional closed nozzle of the injection molding machine, a plunger type or a pull-out type switch is generally used to switch the inner hole of the flow channel. For example, the self-locking nozzle for the injection molding machine of the Chinese patent CN102529024B includes a nozzle body, a nozzle head, a needle valve, a cylinder body and a push rod. The nozzle head is installed at the front end of the nozzle body, the nozzle body is provided with a slide groove, the cylinder body can be slidably sleeved on the nozzle body, an air cavity is formed between the cylinder body and the nozzle body, the cylinder body is provided with an air inlet hole connecting the air cavity, the push rod is inserted in the slide groove and fixed to the cylinder body, the nozzle body is provided with a guide hole, the needle valve is inserted in the guide hole, and the nozzle head is provided with a discharge port. When in use, the air cavity is filled with compressed gas through the air inlet hole, and the cylinder body drives the push rod to move along the slide groove toward the nozzle head under the action of the compressed gas to press the needle valve, and the needle valve moves toward the discharge port under the pressing action of the push rod to close the discharge port to form a self-locking.

[0004] However, plunger-type or pull-out switches are prone to impacting the melt during the extension and retraction process, generating shear heat to the molten material, or closing the flow channel before the molten plastic has cooled down, causing the molten plastic to easily remain on the plunger end face of the switch. Over time, the molten plastic is prone to cooling and accumulating, turning yellow and producing black spots. This not only easily causes a gap between the switch and the flow channel, resulting in a poor seal, but the residual plastic can also cause abnormalities in product quality during injection molding. Moreover, since the plug-in switch and the plunger switch are completely in the material tube or nozzle, the material tube or nozzle needs to be completely disassembled for inspection or maintenance, which makes the maintenance work more complicated and takes a long time, resulting in high maintenance costs. In order to solve the above problems, a rotary valve type closed nozzle and a material tube are proposed. Summary of the invention

[0005] In order to solve the problem in the prior art that the material pipe or nozzle needs to be completely disassembled during inspection or maintenance, which results in complicated maintenance work and long maintenance time, the present invention provides a rotary valve type closed nozzle and a material pipe.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A rotary valve type closed nozzle of the present invention comprises a transition nozzle, a valve core assembly and a positioning cylinder, wherein the positioning cylinder is arranged on the transition nozzle, an injection channel and a valve core channel are provided in the transition nozzle, the injection channel and the valve core channel intersect vertically, one end of the valve core assembly is rotatably arranged in the valve core channel, the other end of the valve core assembly extends out of the transition nozzle and is transmission-connected to the positioning cylinder, and the positioning cylinder drives the valve core assembly to rotate to open or close the injection channel.

[0008] Furthermore, the valve core assembly includes a top pressure cover, a rotating valve core, a bottom pressure cover and a rotating shaft core, the top pressure cover is detachably installed on the top of the valve core channel, the rotating valve core is rotatably arranged in the valve core channel and is rotatably connected to the top pressure cover, the rotating shaft core is transmission-connected to the rotating valve core, the bottom pressure cover abuts against the shoulder of the rotating shaft core and is detachably connected to the bottom of the valve core channel, and the rotating shaft core is transmission-connected to the positioning cylinder.

[0009] Furthermore, the rotating valve core and the rotating shaft core are both provided with key slots and are connected through flat key transmission.

[0010] Furthermore, teeth are arranged on the bottom side of the rotating shaft core, teeth are arranged on the output shaft of the positioning oil cylinder, and the rotating shaft core is meshed with the output shaft of the positioning oil cylinder.

[0011] Furthermore, it also includes a cylinder fixing seat, the cylinder fixing seat is connected to the transition nozzle, the bottom pressure cover is rotatably connected to the cylinder fixing seat, and the positioning cylinder is detachably connected to the cylinder fixing seat.

[0012] Furthermore, the front end and the rear end of the transition nozzle are respectively provided with a front end mounting groove and a rear end mounting groove communicated with the injection channel, and the front end nozzle and the rear end connector are respectively installed in the front end mounting groove and the rear end mounting groove.

[0013] Furthermore, it also includes a fastening nut, the rear end connector is threadedly connected to the fastening nut, and the fastening nut is detachably connected to the rear end of the transition nozzle.

[0014] A material pipe of a rotary valve type closed nozzle also includes a material pipe, and the material pipe is detachably connected to the rear end connector.

[0015] The beneficial effects of the present invention are:

[0016] (1) An injection channel is provided on the axis of the transition nozzle, and a valve core channel is provided on the rim surface of the transition nozzle, that is, on the side perpendicular to the axis. The valve core channel and the injection channel form a cross, so that the valve core assembly can be rotated and installed in the valve core channel. At the same time, the output shaft of the positioning oil cylinder is driven by telescopic drive to drive the valve core assembly so that the valve core assembly rotates accordingly. Since the valve core assembly is installed from the rim surface of the transition nozzle, it can be directly removed from the side of the transition nozzle during maintenance. The valve core assembly has no structure protruding from the valve core channel, so it is relatively simple to disassemble, which can shorten the maintenance time and improve work efficiency.

[0017] (2) During installation, the rotating valve core is pushed upward by the rotating shaft core and is limited in the circular groove of the top gland, while the rotating shaft core is limited by the bottom gland, which can prevent the two from loosening. When disassembly is required, only the bottom gland needs to be removed, and then the rotating shaft core and the rotating valve core can be removed. Due to the streamlined structure, not only can the leakage of molten plastic be reduced, but also the efficiency of installation and disassembly can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0019] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the main cross-sectional structure of the present invention;

[0021] Figure 3 It is a schematic diagram of the internal structure of the main body of the present invention;

[0022] Figure 4 It is a schematic diagram of the structure of the valve core assembly of the present invention;

[0023] Figure 5 It is a schematic diagram of the overall structure of the present invention.

[0024] Legend: 1. Material pipe; 2. Transition nozzle; 3. Positioning cylinder; 4. Valve core assembly; 41. Top pressure cover; 42. Rotating valve core; 43. Rotating shaft core; 44. Flat key; 5. Front nozzle; 6. Rear connector; 7. Cylinder fixing seat; 8. Fastening nut; 9. Bottom pressure cover. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0026] like Figure 1-Figure 5 As shown, a rotary valve type closed nozzle of the present invention comprises a transition nozzle 2, a valve core assembly 4 and a positioning cylinder 3, wherein the positioning cylinder 3 is arranged on the transition nozzle 2, an injection flow channel and a valve core channel are provided in the transition nozzle 2, the injection flow channel and the valve core channel intersect vertically, one end of the valve core assembly 4 is rotatably arranged in the valve core channel, and the other end of the valve core assembly 4 extends out of the transition nozzle 2 and is transmission-connected to the positioning cylinder 3, and the positioning cylinder 3 drives the valve core assembly 4 to rotate to open or close the injection flow channel;

[0027] During the extension and retraction process, plunger-type or pull-out switches are prone to impact on the melt, generate shear heat on the molten material, or close the flow channel before the molten plastic cools down, causing the molten plastic to easily remain on the plunger end face of the switch. Over time, the molten plastic is prone to cooling and accumulating, turning yellow and producing black spots. This not only easily causes a gap between the switch and the flow channel, resulting in a poor seal, but the residual plastic will also cause abnormalities in product quality during injection molding. In addition, since the plug-in switch and plunger switch are completely in the material tube 1 or the nozzle, the material tube 1 or the nozzle needs to be completely disassembled for inspection or maintenance, which makes the maintenance work more complicated and takes a long time, resulting in higher maintenance costs;

[0028] In order to facilitate the cleaning or replacement of the structure used for the flow channel switch during maintenance and overhaul, the existing plunger-type or plug-in switch is replaced with a valve core assembly 4, and the valve core assembly 4 is used to control the on-off of the injection flow channel inside the transition nozzle 2; specifically, an injection flow channel is opened on the axis of the transition nozzle 2, and the injection flow channel is used for the molten plastic to flow out. A valve core channel is opened on the rim surface of the transition nozzle 2, that is, on the side perpendicular to the axis. The valve core channel and the injection flow channel form a cross, so that the valve core assembly 4 can be rotated and fitted in the valve core channel. At the same time, the output shaft of the positioning cylinder 3 is driven by telescopic drive to drive the valve core assembly 4 so that the valve core assembly 4 rotates accordingly. Since the valve core assembly 4 is installed from the rim surface of the transition nozzle 2, it can be directly removed from the side of the transition nozzle 2 during maintenance, and the valve core assembly 4 has no structure protruding from the valve core channel, so the disassembly is also relatively simple, which can shorten the maintenance time and improve the work efficiency during maintenance.

[0029] Since the temperature inside the transition nozzle 2 is relatively high during the operation of the injection molding machine, when used in such an environment, if the connection strength of the valve core assembly 4 is insufficient, the valve core assembly 4 may easily fall off the transition nozzle 2. Therefore, in order to stably install the valve core assembly 4 in the valve core channel and facilitate the installation of the valve core assembly 4, in one embodiment, the valve core assembly 4 includes a top pressure cap 41, a rotating valve core 42, a bottom pressure cap 9 and a rotating shaft core 43. The top pressure cap 41 is detachably installed on the top of the valve core channel, the rotating valve core 42 is rotatably arranged in the valve core channel and is rotatably connected to the top pressure cap 41, a valve core flow channel is provided on the rotating valve core 42, the rotating shaft core is transmission-connected to the rotating valve core 42, the bottom pressure cap 9 abuts against the shaft shoulder of the rotating shaft core and is detachably connected to the bottom of the valve core channel, and the rotating shaft core is transmission-connected to the positioning cylinder 3;

[0030] During the installation process, the top pressure cap 41 needs to be installed first. A top mounting groove for installing the top pressure cap 41 is opened at the top position of the transition nozzle 2 in the valve core channel. Threads are arranged on the top pressure cap 41 and the top mounting groove. The top pressure cap 41 is connected to the top mounting groove by threads. Since the diameter of the top mounting groove is larger than the valve core channel, after the top pressure cap 41 is tightened, the bottom of the top pressure cap 41 abuts against the top of the top mounting groove, forming a larger contact surface, which can prevent the molten plastic from flowing out of the gap between the valve core channel and the top pressure cap 41 during the injection molding process. Then the rotating valve core 42 is installed upward from the bottom of the valve core channel. A circular groove is opened at the bottom of the top pressure cap 41, and the rotating valve core 42 can be rotatably installed in the circular groove, and then it is pressed against the shoulder of the rotating shaft core through the bottom pressure cap 9, and the bottom pressure cap 9 is connected to the bottom of the transition nozzle 2 by bolts. After the bottom gland 9 is installed, the rotary valve core 42 is limited in the circular groove of the top gland 41 by the upward push of the rotary shaft core 43, and the rotary shaft core 43 is limited by the bottom gland 9, which can prevent the two from loosening. When disassembly is required, it is only necessary to disassemble the bottom gland 9, and then disassemble the rotary shaft core 43 and the rotary valve core 42. Due to the streamlined structure, not only can the leakage of molten plastic be reduced, but also the efficiency of installation and disassembly can be improved.

[0031] The valve core flow channel on the rotating valve core 42 can only allow the molten plastic to flow out of the injection flow channel after the valve core flow channel is rotated to coincide with the injection flow channel. When the valve core flow channel abuts against the side wall of the valve core channel and the side wall of the rotating valve core 42 abuts against and blocks the injection flow channel, the molten plastic cannot flow out. Since the fitting surface between the rotating valve core 42 and the injection flow channel is larger, the molten plastic can be prevented from leaking out. After the valve core flow channel and the injection flow channel coincide with each other again, the newly extruded molten plastic in the injection flow channel can also squeeze out the solidified plastic in the valve core flow channel. The molten plastic flowing through at high temperature can also peel off the residual plastic in the valve core flow channel, thereby cleaning the valve core flow channel.

[0032] Since the internal temperature of the transition nozzle 2 is high when the injection molding machine is running, when the switch structure inside it is relatively complex, it is easy to cause the switch to fail due to the different thermal expansion coefficients of different structures due to thermal expansion and contraction, resulting in a matching gap or heat transfer to the drive device. In order to avoid this problem, in one embodiment, the rotating valve core 42 and the rotating shaft core are both provided with a keyway and are connected by a flat key 44; the flat key 44 is connected to the keyway of the rotating shaft core 43 through a connecting piece, and then connected to the keyway on the rotating valve core 42. Since the rotating valve core 42 is limited, the connection method through the flat key 44 is relatively simple, which can reduce the problem of matching gap caused by different thermal expansion coefficients of different structures. At the same time, the rotating valve core 42 and the rotating shaft core 43 are connected by the flat key 44, which can also reduce the transfer of heat, avoid the temperature of the molten plastic in the injection flow channel from being directly transferred to the positioning cylinder 3 through the rotating valve core 42 and the rotating shaft core 43, and can reduce the probability of failure of the positioning cylinder 3.

[0033] Specifically, teeth are provided on the bottom side of the rotating shaft core 43, and teeth are provided on the output shaft of the positioning cylinder 3. The rotating shaft core 43 is meshed with the output shaft of the positioning cylinder 3. The bottom of the rotating shaft core 43 is a gear structure, and the output shaft of the positioning cylinder 3 is a rack mechanism. The output shaft is driven by the positioning cylinder 3 to extend and retract, so that the rotating shaft core 43 is rotated to control the on-off of the valve core flow channel and the injection flow channel.

[0034] Furthermore, it also includes a cylinder fixing seat 7, which is a right-angle structure. The top horizontal section of the cylinder fixing seat 7 is connected to the transition nozzle 2, the bottom pressure cover 9 is rotatably connected to the horizontal section of the cylinder fixing seat 7, and the positioning cylinder 3 is detachably connected to the vertical section of the cylinder fixing seat 7.

[0035] Furthermore, the front end and rear end of the transition nozzle 2 are respectively provided with a front end mounting groove and a rear end mounting groove connected to the injection channel, and the front end nozzle 5 and the rear end connector 6 are respectively installed in the front end mounting groove and the rear end mounting groove; after the front end nozzle 5 and the rear end connector 6 are installed in the front end mounting groove and the rear end mounting groove, the front end nozzle 5 and the rear end connector 6 are respectively fitted with the side walls of the front end mounting groove and the rear end mounting groove, and the leakage of the molten plastic can be reduced by increasing their contact area.

[0036] Furthermore, it also includes a fastening nut 8, the rear end connector 6 is threadedly connected to the fastening nut 8, and the fastening nut 8 is detachably connected to the rear end of the transition nozzle 2; specifically, a plurality of bolt holes are provided on the fastening nut 8, the fastening nut 8 is connected to the transition nozzle 2 by bolts, and then the rear end connector 6 is tightened on the fastening nut 8.

[0037] A material pipe 1 of a rotary valve type closed nozzle also includes a material pipe 1, and the material pipe 1 is detachably connected to a rear end connector 6.

[0038] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A rotary valve type closed nozzle, characterized in that: It includes a transition nozzle, a valve core assembly and a positioning cylinder, wherein the positioning cylinder is arranged on the transition nozzle, an injection channel and a valve core channel are provided in the transition nozzle, the injection channel and the valve core channel intersect vertically, one end of the valve core assembly is rotatably arranged in the valve core channel, the other end of the valve core assembly extends out of the transition nozzle and is transmission-connected to the positioning cylinder, and the positioning cylinder drives the valve core assembly to rotate to open or close the injection channel.

2. A rotary valve type closed nozzle according to claim 1, characterized in that: The valve core assembly includes a top pressure cover, a rotating valve core, a bottom pressure cover and a rotating shaft core. The top pressure cover is detachably installed on the top of the valve core channel. The rotating valve core is rotatably arranged in the valve core channel and is rotatably connected to the top pressure cover. A valve core flow channel is opened on the rotating valve core. The rotating shaft core is transmission-connected to the rotating valve core. The bottom pressure cover abuts against the shoulder of the rotating shaft core and is detachably connected to the bottom of the valve core channel. The rotating shaft core is transmission-connected to the positioning cylinder.

3. A rotary valve type closed nozzle according to claim 2, characterized in that: The rotary valve core and the rotary shaft core are both provided with keyways and are connected through flat keys.

4. A rotary valve type closed nozzle according to claim 2, characterized in that: The bottom side of the rotating shaft core is provided with teeth, the output shaft of the positioning oil cylinder is provided with teeth, and the rotating shaft core is meshed with the output shaft of the positioning oil cylinder.

5. A rotary valve type closed nozzle according to claim 2, characterized in that: It also includes a cylinder fixing seat, which is connected to the transition nozzle, the bottom pressure cover is rotatably connected to the cylinder fixing seat, and the positioning cylinder is detachably connected to the cylinder fixing seat.

6. The rotary valve type closed nozzle according to claim 1, characterized in that: The front end and the rear end of the transition nozzle are respectively provided with a front end mounting groove and a rear end mounting groove communicated with the injection flow channel, and the front end nozzle and the rear end connector are respectively installed in the front end mounting groove and the rear end mounting groove.

7. A rotary valve type closed nozzle according to claim 6, characterized in that: It also includes a fastening nut, the rear end connector is threadedly connected to the fastening nut, and the fastening nut is detachably connected to the rear end of the transition nozzle.

8. A material pipe of a rotary valve type closed nozzle, which is suitable for a rotary valve type closed nozzle as claimed in claim 7, characterized in that: It also includes a material pipe, which is detachably connected to the rear end connector.

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