Needle valve type air cylinder structure and injection mold

Abstract

The utility model relates to the technical field of air cylinders, in particular to a needle valve type air cylinder structure and an injection mold. The needle valve type air cylinder structure comprises an air cylinder cover which is provided with a movable cavity with a downward opening. The piston is movably arranged in the movable cavity; the bottom end of the cylinder cover is connected with the guide sleeve; one end of the valve needle is connected with the piston, the other end of the valve needle is movably arranged in the guide sleeve, the tail end of the valve needle extends out of the outer side of the guide sleeve, and the valve needle, the guide sleeve and the piston are coaxially arranged. The cylinder cover and the guide sleeve are designed to be two split independent parts, so that the machining process of parts is simplified, the concentricity and the coaxiality of all hole channels in the cylinder are better guaranteed, and the service life of the valve needle and the service life of the guide sleeve are prolonged; and the contact area with a hot runner is reduced, so that the mold is more stable to use.

Description

Technical Field

[0001] The utility model relates to the technical field of cylinders, in particular to a needle valve type cylinder structure and an injection mold. Background Art

[0002] Hot runner needle valve molding mold is one of the equipment used in PET preform production. Due to the advantages of hot runner molds such as faster heating, more uniform temperature distribution, more convenient color change and longer service life, they are widely used in PET preform production.

[0003] However, the cylinder of traditional PET needle valve molds is mostly an integral structure, which is relatively complex in overall structure and production and processing. The heat transfer is fast, which can easily cause the PET raw materials to gasify under high temperature conditions, forming high-temperature rubber dust or causing glue leakage. Continuous high temperature can also easily cause the piston seal to melt and fail, greatly reducing the service life of the seal. Utility Model Content

[0004] The utility model aims to provide a needle valve type cylinder structure and an injection mold, aiming to solve the technical problems that the existing PET needle valve type molds are mostly split structures, the overall structure is relatively complex, and the heat transfer is fast, high-temperature glue dust is easily formed or glue leakage occurs easily.

[0005] To achieve the above-mentioned purpose, the utility model provides a needle valve type cylinder structure, including a cylinder head, which has an active cavity with an opening facing downward;

[0006] a piston movably disposed in the movable chamber;

[0007] A guide sleeve, the bottom end of the cylinder head is connected to the guide sleeve;

[0008] A valve needle, one end of which is connected to the piston, and the other end of which is movably arranged in the guide sleeve, and the end of the valve needle extends to the outside of the guide sleeve. The valve needle, the guide sleeve and the piston are coaxially arranged, so that when the piston drives the valve needle to move synchronously, the glue outlet of the injection mold is blocked or opened.

[0009] Preferably, an annular protrusion is provided on the outer wall of the piston, an end of the protrusion contacts the inner wall of the active chamber, and the protrusion separates the piston into a first part and a second part, and the first part is located above the second part.

[0010] Preferably, an annular installation groove is provided on the outer side of the protruding portion, a sealing ring is provided in the installation groove, and the sealing ring abuts against the inner wall of the movable cavity.

[0011] Preferably, the guide sleeve includes a head, a neck and a bottom connected in sequence, the outer diameter of the head is greater than the outer diameter of the neck, and the outer diameter of the neck gradually decreases from the side close to the head to the side away from the head, and the outer diameter of the bottom end of the neck is greater than the outer diameter of the bottom, so that the connection between the bottom end of the neck and the outer wall of the bottom is stepped.

[0012] Preferably, the guide sleeve is provided with a plurality of air inlets, the inner wall of the cylinder head, the outer wall of the piston, the bottom end of the protrusion and the top end of the guide sleeve together form an air inlet cavity, and the air inlets are communicated with the air inlet cavity;

[0013] The bottom end of the protruding portion is recessed inward to form a first groove, and the top end of the guide sleeve is recessed inward to form a second groove. Both the first groove and the second groove are communicated with the air inlet cavity.

[0014] Preferably, the interior of the piston is provided with a first through hole, a second through hole and a through hole which are connected in sequence, the diameter of the first through hole is greater than the diameter of the second through hole and the diameter of the through hole, a sealing member is provided in the first through hole, the bottom end of the sealing member is connected to the top end of the valve needle, one end of the valve needle is installed in the second through hole, and the other end thereof passes through the through hole and extends into the guide sleeve.

[0015] Preferably, a through movable channel is provided in the guide sleeve, the valve needle is movably arranged in the movable channel, and a glue overflow hole is also provided in the guide sleeve, and the glue overflow hole is communicated with the movable channel.

[0016] Preferably, a mounting hole is provided in the head portion, and the bottom end of the cylinder head is arranged in the mounting hole.

[0017] Preferably, the outer wall at the top end of the neck is recessed inward to form a void portion.

[0018] In addition, the utility model also provides an injection mold, which is provided with a plurality of needle valve type cylinder structures described in any one of the above items.

[0019] The utility model discloses a needle valve type cylinder structure and an injection mold, which have the following beneficial effects: by designing a cylinder cover and a guide sleeve as two separate components, they can be processed separately, thereby simplifying the processing technology of parts; at the same time, the separate processing can reduce errors, improve processing accuracy, better ensure the concentricity and coaxiality of each channel for the movement of the valve needle, reduce the wear between the valve needle and the valve needle, and effectively extend the service life of the valve needle and the guide sleeve; in addition, after the cylinder is divided into the guide sleeve and the cylinder cover, the wall thickness of the cylinder cover can be appropriately thinned according to demand, thereby reducing the contact area with the hot runner, making other parts more durable and the mold more stable to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the cross-sectional structure of a traditional needle valve type cylinder structure;

[0022] Figure 2 This is a schematic diagram of the structure of the needle valve type cylinder structure of the utility model;

[0023] Figure 3 It is a cross-sectional structural diagram of the needle valve type cylinder structure of the utility model;

[0024] Figure 4 It is an exploded view of the needle valve type cylinder structure of the utility model;

[0025] Figure 5 It is a schematic diagram of the cross-sectional structure of the needle valve type cylinder structure of the utility model after explosion.

[0026] In the accompanying drawings: 1-cylinder head, 11-active chamber, 2-piston, 21-protrusion, 211-mounting groove, 212-first groove, 22-first part, 23-second part, 24-sealing ring, 25-first through hole, 26-second through hole, 27-through hole, 28-blocking piece, 3-guide sleeve, 31-head, 311-mounting hole, 32-neck, 321-air avoidance part, 33-bottom, 34-air inlet, 35-second groove, 36-active channel, 37-overflow hole, 4-valve needle, 5-inlet chamber.

[0027] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] It should be noted that if a directional indication is involved in the embodiments of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0031] A needle valve type cylinder structure comprises a cylinder head 1 having an active chamber 11 with an opening facing downward;

[0032] A piston 2, which is movably arranged in the movable chamber 11;

[0033] A guide sleeve 3, to which the bottom end of the cylinder head 1 is connected;

[0034] A valve needle 4, one end of which is connected to the piston 2, and the other end of which is movably arranged in the guide sleeve 3, and the end of the valve needle 4 extends to the outside of the guide sleeve 3. The valve needle 4, the guide sleeve 3 and the piston 2 are coaxially arranged, so that when the piston 2 drives the valve needle 4 to move synchronously, the glue outlet of the injection mold is blocked or opened.

[0035] like Figure 1 As shown, the cylinder of the traditional PET needle valve mold adopts a more complex integral structure, and the cylinder processing process is more difficult; and the contact surface a between the cylinder and the hot runner is larger, and the heat transfer is faster.

[0036] like Figures 2 to 5As shown, this solution provides a new needle valve hot runner cylinder structure for a PET preform mold. The cylinder is a split structure, specifically, the cylinder head 1 and the guide sleeve 3 are designed as two independent components. Therefore, the two can be processed separately, without processing more complex structures inside the traditional cylinder, which simplifies the processing technology of the parts, making the cylinder production and processing of this solution relatively much easier; at the same time, the split processing can reduce errors, improve processing accuracy, better ensure the concentricity and coaxiality of each channel for the movement of the valve needle 4, reduce the wear between the valve needle 4, and effectively extend the service life of the valve needle 4 and the guide sleeve 3. After the cylinder is divided into two parts, the guide sleeve 3 and the cylinder head 1, the wall thickness of the cylinder head 1 can be appropriately thinned according to demand, reducing the contact area with the hot runner, making other parts more durable, and the mold more stable to use.

[0037] Furthermore, an annular protrusion 21 is provided on the outer wall of the piston 2 , and the end of the protrusion 21 contacts the inner wall of the active chamber 11 . The protrusion 21 separates the piston 2 into a first part 22 and a second part 23 , and the first part 22 is located above the second part 23 .

[0038] The protrusion 21 is usually an integrated structure with the piston 2, and the two move up and down together in the active chamber 11. Gas enters from the top of the cylinder head 1 through the air supply channel, squeezes the piston 2 to move it downward, and the needle valve moves downward synchronously to block the glue outlet of the injection mold (not shown in the figure); another group of gas enters the cylinder head 1 from the valve sleeve through the air supply channel, lifts the piston 2 to move it upward, and the needle valve moves upward synchronously to open the glue outlet of the injection mold. When the piston 2 moves downward, the bottom end of the second part 23 abuts against the top end of the guide sleeve 3, and the top end of the guide sleeve 3 limits the piston 2.

[0039] Furthermore, an annular mounting groove 211 is provided on the outer side of the protrusion 21, and a sealing ring 24 is provided in the mounting groove 211, and the sealing ring 24 abuts against the inner wall of the active cavity 11. The sealing ring 24 is located on the outer circumferential side of the protrusion 21, and contacts the inner wall of the active cavity 11, which can increase the air tightness between the piston 2 and the cavity at its upper end, and prevent the gas between the upper cavity and the lower cavity of the piston 2 from communicating with each other, thereby affecting the normal operation of the piston 2.

[0040] Furthermore, the guide sleeve 3 includes a head 31, a neck 32 and a bottom 33 connected in sequence, the outer diameter of the head 31 is greater than the outer diameter of the neck 32, and the outer diameter of the neck 32 gradually decreases from the side close to the head 31 to the side away from the head 31, and the outer diameter of the bottom end of the neck 32 is greater than the outer diameter of the bottom 33, so that the connection between the bottom end of the neck 32 and the outer wall of the bottom 33 is stepped.

[0041] The guide sleeve 3 is set to the above structure, and the outer diameter of the neck 32 of the guide sleeve 3 is gradually reduced, and the area of ​​its bottom end is also gradually reduced, which can further reduce the contact area between the cylinder structure and the hot runner, reduce heat transfer, and effectively extend the service life of the sealing ring 24 on the piston 2 (protrusion 21), thereby ensuring the stability of the mold and greatly reducing the dust and glue leakage caused by high temperature.

[0042] The guide sleeve 3 has a stepped neck 32 and a bottom 33, which is mainly for better clamping in the hot runner. The hot runner is provided with corresponding holes for the cylinder structure of this solution to be installed.

[0043] Furthermore, the guide sleeve 3 is provided with a plurality of air inlets 34, the inner wall of the cylinder head 1, the outer wall of the piston 2, the bottom end of the protrusion 21 and the top end of the guide sleeve 3 together form an air inlet cavity 5, and the air inlets 34 are in communication with the air inlet cavity 5;

[0044] The bottom end of the protrusion 21 is recessed inward to form a first groove 212 , and the top end of the guide sleeve 3 is recessed inward to form a second groove 35 . Both the first groove 212 and the second groove 35 are connected to the air inlet cavity 5 .

[0045] When it is necessary to drive the piston 2 to move upward, the gas enters the air inlet chamber 5 from the valve sleeve air inlet 34 through the air supply channel. A first groove 212 is provided on the protrusion 21, and a second groove 35 is provided on the guide sleeve 3. Both are connected with the air inlet chamber 5, thereby expanding the volume of the air inlet chamber 5, and can more stably lift the piston 2 to move upward, so that the needle valve moves upward synchronously, and the glue outlet of the injection mold is opened.

[0046] Furthermore, the interior of the piston 2 is provided with a first through hole 25, a second through hole 26 and a through hole 27 which are connected in sequence, the diameter of the first through hole 25 is greater than the diameter of the second through hole 26 and the diameter of the through hole 27, a blocking member 28 is provided in the first through hole 25, the bottom end of the blocking member 28 is connected to the top end of the valve needle 4, one end of the valve needle 4 is installed in the second through hole 26, and the other end thereof passes through the through hole 27 and extends into the guide sleeve 3.

[0047] Usually, a threaded hole is provided inside the first through hole 25 at the top of the piston 2. The plugging member 28 is a screw plug in actual production. The plugging member 28 (screw plug) is threadedly connected in the threaded hole. The top of the valve needle 4 is fixed in the threaded first through hole 25 through the plugging member 28. The top of the valve needle 4 has a larger diameter and can be better fixed in the second through hole 26.

[0048] Furthermore, the guide sleeve 3 is provided with a through movable channel 36, the valve needle 4 is movably arranged in the movable channel 36, and the guide sleeve 3 is also provided with a glue overflow hole 37.

[0049] Connected with the active channel 36. Figure 3 As shown, one end of the valve needle 4 passes through the through hole 27 and

[0050] The movable channel 36 can move up and down, and the movable channel 36 is connected to the outside. Under high temperature conditions, the PET 5 will be partially gasified, and after gasification, it can enter the overflow hole 37 along the movable channel 36 of the guide sleeve 3. Otherwise,

[0051] After long-term use, the movable channel 36 will be blocked, affecting the normal operation of the cylinder.

[0052] Furthermore, a mounting hole 311 is provided in the head 31, and the bottom end of the cylinder head 1 is arranged in the mounting hole 311. The top of the head 31 of the guide sleeve 3 is provided with a mounting hole 311, and the inner diameter of the mounting hole 311 is slightly larger than the outer diameter of the cylinder head 1, so that the cylinder head 1 can be inserted into the mounting hole 311. After the needle valve cylinder structure of this scheme 0 is installed in the hot runner, the guide sleeve 3 is installed in the hole position of the hot runner plate.

[0053] At this time, the cylinder head 1 and the inner wall of the mounting hole 311 of the head 31 of the guide sleeve 3 are tightly fitted, and the sealing performance is good.

[0054] Furthermore, the outer wall at the top of the neck 32 is recessed inward to form a voiding portion 321. The arrangement of the voiding portion 321 allows the guide sleeve 3 to be more closely mounted on the hole of the heat flux plate.

[0055] In addition, the utility model also proposes an injection mold, which is provided with a plurality of needle valve type cylinder structures described in any one of the above 5 items.

[0056] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All the inventions in the utility model specification and drawings are

[0057] The equivalent structural transformations made to the content, or direct / indirect application in other related technical fields are all included in the patent protection scope of this utility model.

Claims

1. A needle valve cylinder structure, characterized in that: include: A cylinder head (1) having a movable chamber (11) with an opening facing downward; A piston (2) movably disposed in the movable chamber (11); A guide sleeve (3), the bottom end of the cylinder head (1) being connected to the guide sleeve (3); A valve needle (4), one end of the valve needle (4) is connected to the piston (2), and the other end of the valve needle (4) is movably arranged in the guide sleeve (3), and the end of the valve needle (4) extends to the outside of the guide sleeve (3). The valve needle (4), the guide sleeve (3) and the piston (2) are coaxially arranged, so that when the piston (2) drives the valve needle (4) to move synchronously, the glue outlet of the injection mold is blocked or opened.

2. A needle valve type cylinder structure according to claim 1, characterized in that: The outer wall of the piston (2) is provided with an annular protrusion (21), the end of the protrusion (21) contacts the inner wall of the active chamber (11), and the protrusion (21) separates the piston (2) into a first part (22) and a second part (23), wherein the first part (22) is located above the second part (23).

3. A needle valve type cylinder structure according to claim 2, characterized in that: An annular mounting groove (211) is provided on the outer side of the protruding portion (21), a sealing ring (24) is provided in the mounting groove (211), and the sealing ring (24) abuts against the inner wall of the active cavity (11).

4. A needle valve type cylinder structure according to claim 1, characterized in that: The guide sleeve (3) comprises a head (31), a neck (32) and a bottom (33) which are connected in sequence, the outer diameter of the head (31) is greater than the outer diameter of the neck (32), and the outer diameter of the neck (32) gradually decreases from a side close to the head (31) to a side far from the head (31), and the outer diameter of the bottom end of the neck (32) is greater than the outer diameter of the bottom (33), so that the connection between the bottom end of the neck (32) and the outer wall of the bottom (33) is stepped.

5. The needle valve type cylinder structure according to claim 2, characterized in that: The guide sleeve (3) is provided with a plurality of air inlets (34); the inner wall of the cylinder head (1), the outer wall of the piston (2), the bottom end of the protrusion (21) and the top end of the guide sleeve (3) together form an air inlet cavity (5); and the air inlets (34) are in communication with the air inlet cavity (5); The bottom end of the protruding portion (21) is recessed inwardly to form a first groove (212), and the top end of the guide sleeve (3) is recessed inwardly to form a second groove (35). Both the first groove (212) and the second groove (35) are connected to the air inlet cavity (5).

6. The needle valve type cylinder structure according to claim 1, characterized in that: The interior of the piston (2) is provided with a first through hole (25), a second through hole (26) and a through hole (27) which are connected in sequence, the diameter of the first through hole (25) being greater than the diameter of the second through hole (26) and greater than the diameter of the through hole (27), a sealing member (28) is provided in the first through hole (25), the bottom end of the sealing member (28) is connected to the top end of the valve needle (4), one end of the valve needle (4) is installed in the second through hole (26), and the other end thereof passes through the through hole (27) and extends into the guide sleeve (3).

7. The needle valve type cylinder structure according to claim 1, characterized in that: The guide sleeve (3) is provided with a through movable channel (36), the valve needle (4) is movably arranged in the movable channel (36), and the guide sleeve (3) is also provided with a glue overflow hole (37), the glue overflow hole (37) is communicated with the movable channel (36).

8. The needle valve type cylinder structure according to claim 4, characterized in that: A mounting hole (311) is provided in the head portion (31), and the bottom end of the cylinder head (1) is arranged in the mounting hole (311).

9. The needle valve type cylinder structure according to claim 4, characterized in that: The outer wall of the top end of the neck (32) is recessed inwards to form a void portion (321).

10. An injection mold, characterized in that: It is provided with a plurality of needle valve type cylinder structures as described in any one of claims 1-9.

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