Wear-resistant and heat-resistant valve needle sleeve

Abstract

The utility model relates to technical field of valve needle cover, propose a kind of wear-resistant heat-resistant valve needle cover, including end cover, locking sleeve, heat insulation sealing ring and wear-resistant cover;Locking sleeve and wear-resistant cover are respectively provided with valve needle hole along vertical direction;The bottom surface of locking sleeve is inwardly recessed and provided with mounting groove, and the valve needle hole of locking sleeve is communicated with mounting groove;Wear-resistant cover is set in mounting groove;Heat insulation sealing ring is set between wear-resistant cover and the bottom wall of mounting groove;The inner wall of the valve needle hole of wear-resistant cover is provided with wear-resistant layer, and wear-resistant layer is prepared from ceramic material;End cover is fixedly installed on shunt plate, shunt plate is provided with positioning groove, and end cover is compressed in positioning groove by locking sleeve and wear-resistant cover through locking part;The wear-resistant cover of valve needle cover of the utility model adopts ceramic material, not only wear-resistant heat-resistant, and can effectively prolong service life, reduce maintenance cost.

Description

Technical Field

[0001] This utility model relates to the technical field of valve needle sleeves, and in particular to a wear-resistant and heat-resistant valve needle sleeve. Background Technology

[0002] In hot runner systems, the valve pin sleeve is a key component of valve-type hot nozzles. The valve pin sleeve is usually installed at the tip of the hot nozzle. Together with the valve pin and the hydraulic / pneumatic cylinder drive mechanism, it forms the valve pin system, which is the last "checkpoint" through which molten plastic flows. Its opening and closing directly controls the filling of the mold cavity. Especially under high-pressure and high-temperature conditions such as injection molding and automotive fuel injection, the existing valve pin sleeve technology is insufficient in terms of wear resistance and heat resistance, resulting in short valve pin sleeve life, short replacement cycle, and high maintenance costs. It has become a prominent obstacle hindering the upgrading of related industries towards higher efficiency, higher precision, and higher reliability. Utility Model Content

[0003] To address the aforementioned shortcomings, the purpose of this invention is to propose a wear-resistant and heat-resistant valve needle sleeve, thereby solving the problems of existing valve needle sleeves being neither wear-resistant nor heat-resistant, having a short lifespan, and incurring high maintenance costs.

[0004] To achieve this objective, the present invention adopts the following technical solution: A wear-resistant and heat-resistant valve needle sleeve includes an end cap, a locking sleeve, a heat-insulating sealing ring, and a wear-resistant sleeve; The locking sleeve and the wear-resistant sleeve are respectively provided with valve pin holes in the vertical direction; The bottom surface of the locking sleeve is recessed inward and has a mounting groove, which communicates with the valve pin hole of the locking sleeve. The wear-resistant sleeve is disposed within the mounting groove; the heat-insulating sealing ring is disposed between the wear-resistant sleeve and the bottom wall of the mounting groove; The inner wall of the valve pin hole of the wear-resistant sleeve is provided with a wear-resistant layer, which is made of ceramic material; The end cap is fixedly installed on the diverter plate, the diverter plate is provided with a positioning groove, and the end cap presses the locking sleeve and the wear-resistant sleeve into the positioning groove by a locking member.

[0005] Preferably, the locking sleeve includes a wrench portion, a threaded portion, and a height limiting portion. The wrench portion is disposed at the top of the threaded portion, and the height limiting portion is disposed at the bottom of the threaded portion. The wrench portion is shaped like a hexagonal nut. The threaded portion is provided with external threads, and the sidewall of the positioning groove is provided with internal threads. The threaded portion and the sidewall of the positioning groove are threadedly connected. The height limiting portion is shaped like an annulus.

[0006] Preferably, the edge of the height limiting part is chamfered.

[0007] Preferably, the wear-resistant sleeve is made entirely of ceramic material.

[0008] Preferably, the wear-resistant sleeve comprises, from the inside out, a wear-resistant layer, a high-temperature resistant layer, and a protective layer; the high-temperature resistant layer is made of a nickel-based high-temperature alloy, and the protective layer is made of a chromium alloy.

[0009] Preferably, a heat insulation ring is provided between the wear-resistant sleeve and the locking sleeve, and the heat insulation ring is a PTFE sealing ring.

[0010] Preferably, the outer wall of the heat insulation ring is provided with a first inclined surface, the cross-section of the heat insulation ring is a right trapezoidal shape, the side wall of the mounting groove is also provided with a second inclined surface, the cross-section of the mounting groove is a trapezoidal groove, the maximum outer diameter of the heat insulation ring is larger than the maximum inner diameter of the mounting groove, and the minimum outer diameter of the heat insulation ring is larger than the minimum inner diameter of the mounting groove.

[0011] Preferably, the bottom surface of the end cap is recessed inward and has a pressing groove, and the locking sleeve is disposed in the pressing groove. When the end cap is pressed by the locking member, the top surface of the locking sleeve is in close contact with the bottom of the pressing groove.

[0012] Preferably, the end cap is provided with an anti-rotation threaded hole, and an anti-rotation bolt is threadedly connected to the anti-rotation threaded hole, with the bottom surface of the anti-rotation bolt pressing against the top surface of the locking sleeve.

[0013] One of the above technical solutions has the following advantages or beneficial effects: 1. The inner wall of the valve needle hole of the wear-resistant sleeve is equipped with a ceramic layer. The ceramic material has a hardness, wear resistance and high temperature stability far exceeding that of traditional steel, which solves the problem of high temperature softening of traditional steel. The ceramic layer directly faces the scraping of the valve needle and the scouring of the plastic melt, which can greatly extend the working life, the replacement cycle and the service life. 2. In addition, the heat insulation sealing ring can effectively block the high temperature generated by the wear-resistant sleeve during operation from being conducted to the locking sleeve, so that the locking sleeve can be kept at a relatively low temperature, thereby maintaining its structural strength and dimensional stability, avoiding problems caused by high temperature softening or thermal expansion mismatch, and also compensating for the small displacement caused by the difference in thermal expansion coefficients between the wear-resistant sleeve and the locking sleeve, preventing cracking or deformation caused by thermal stress, and ensuring the positioning accuracy of the wear-resistant sleeve in the working state; 3. The modular design allows for individual replacement of the wear sleeve when it is damaged, without the need to replace the entire locking sleeve or hot nozzle assembly, further reducing maintenance costs. Attached Figure Description

[0014] Figure 1 This is a side sectional view of one embodiment of the present invention; Figure 2 This is a schematic diagram of a heat insulation ring according to one embodiment of the present invention; Figure 3 This is an exploded view of one embodiment of the present invention; Figure 4 This is a schematic diagram of a wear-resistant sleeve according to one embodiment of the present invention; The components include: end cap 1, clamping groove 11, anti-rotation threaded hole 12, anti-rotation bolt 13, locking sleeve 2, valve pin hole 20, mounting groove 21, second inclined surface 211, wrench part 22, threaded part 23, height limiting part 24, chamfer 241, heat insulation sealing ring 3, wear-resistant sleeve 4, wear-resistant layer 41, high temperature resistant layer 42, protective layer 43, flow divider 5, heat insulation ring 6, and first inclined surface 61. Detailed Implementation

[0015] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0016] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, features defined with "first" and "second" may explicitly or implicitly include one or more of these features, used to distinguish and describe features, without any order or emphasis.

[0017] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] The following is combined Figures 1 to 4 A wear-resistant and heat-resistant valve needle sleeve according to an embodiment of the present utility model includes an end cap 1, a locking sleeve 2, a heat insulation sealing ring 3, and a wear-resistant sleeve 4; The locking sleeve 2 and the wear-resistant sleeve 4 are respectively provided with valve pin holes 20 in the vertical direction; The bottom surface of the locking sleeve 2 is recessed inward and has an installation groove 21, which is connected to the valve pin hole 20 of the locking sleeve 2. The wear-resistant sleeve 4 is disposed in the mounting groove 21; the heat-insulating sealing ring 3 is disposed between the wear-resistant sleeve 4 and the bottom wall of the mounting groove 21; The inner wall of the valve pin hole 20 of the wear-resistant sleeve 4 is provided with a wear-resistant layer 41, which is made of ceramic material; The end cap 1 is fixedly installed on the diverter plate 5. The diverter plate 5 is provided with a positioning groove. The end cap 1 presses the locking sleeve 2 and the wear-resistant sleeve 4 into the positioning groove by a locking member.

[0020] Specifically, the locking sleeve 2 is connected to the manifold 5 by screwing and is further pressed onto the manifold 5 by the end cap 1. The locking sleeve 2 is responsible for bearing the main injection pressure, clamping force, and installation preload from the injection molding machine nozzle and mold cavity. Its material can be high-strength, high-toughness alloy steel to ensure the rigidity of the overall structure. The wear-resistant sleeve 4 is embedded in the mounting groove 21 of the locking sleeve 2. Its valve needle hole 20 is the working surface where the valve needle slides directly and forms a seal. The inner wall of the wear-resistant sleeve 4 mainly bears the friction and wear of the valve needle and the high temperature of the sealing surface. Therefore, a ceramic layer is set on the inner wall of the valve needle hole 20 of the wear-resistant sleeve 4. The ceramic material has a hardness, wear resistance, and high-temperature stability far exceeding that of traditional steel. The ceramic material can still maintain its strength and hardness above 1000°C, solving the problem of high-temperature softening of traditional steel. The ceramic layer directly faces the scraping of the valve needle and the scouring of the plastic melt, which can greatly extend the working life, the replacement cycle, and the service life. In addition, the heat insulation sealing ring 3 effectively blocks the high temperature generated by the wear-resistant sleeve 4 during operation from being conducted to the locking sleeve 2. This allows the locking sleeve 2 to maintain a relatively low temperature, thereby preserving its structural strength and dimensional stability, avoiding problems caused by high-temperature softening or thermal expansion mismatch. It also compensates for the slight displacement caused by the difference in thermal expansion coefficients between the wear-resistant sleeve 4 and the locking sleeve 2, preventing cracking or deformation caused by thermal stress, and ensuring the positioning accuracy of the wear-resistant sleeve 4 in the working state. Furthermore, the modular design allows the wear-resistant sleeve 4 to be replaced individually when it is damaged, without having to replace the entire locking sleeve 2 or the hot nozzle assembly, further reducing maintenance costs.

[0021] Furthermore, the locking sleeve 2 includes a wrench portion 22, a threaded portion 23, and a height limiting portion 24. The wrench portion 22 is disposed at the top of the threaded portion 23, and the height limiting portion 24 is disposed at the bottom of the threaded portion 23. The wrench portion 22 is shaped like a hexagonal nut. The threaded portion 23 is provided with external threads, and the sidewall of the positioning groove is provided with internal threads. The threaded portion 23 and the sidewall of the positioning groove are threadedly connected. The height limiting portion 24 is shaped like a ring.

[0022] The height limiter 24 is used to limit the installation depth of the locking sleeve 2, the wrench part 22 is used to facilitate the wrench turning operation, and the threaded part 23 is used to lock the locking sleeve 2 to the positioning groove through the threaded connection, while pressing the wear-resistant sleeve 4 towards the bottom of the positioning groove. The specific installation operation is simple. The operator only needs to put the wear-resistant sleeve 4 and the heat insulation sealing ring 3 into the positioning groove of the diverter plate 5, then put on the locking sleeve 2, and then use the wrench to tighten the locking sleeve 2 until the height limiter 24 contacts it. There is no need to worry about the tightening sequence and torque balance of multiple bolts. When the wrench part 22 is turned, the huge axial tensile force generated by the thread acts directly and evenly on the locking sleeve 2 body, and through its bottom end face, the force is transmitted to the wear-resistant sleeve 4 and the heat insulation sealing ring 3 below without attenuation, and finally presses them into the bottom of the positioning groove. Its pre-tightening force is far greater than that of traditional bolt tightening, ensuring stable sealing of the sealing surface under extreme injection pressure cycles.

[0023] Furthermore, a chamfer 241 is provided at the edge of the height limiting part 24.

[0024] Specifically, during installation, the heat insulation sealing ring 3 and the wear-resistant sleeve 4 are placed into the bottom of the positioning groove of the diverter plate 5 in sequence. Then, the locking sleeve 2 is held and put down from above (on one side of the wrench part 22) so that the wear-resistant sleeve 4 and the heat insulation ring enter the mounting groove 21 inside the locking sleeve 2. During this process, even if there is a slight eccentricity when the locking sleeve 2 falls, the chamfer 241 of its edge will generate a radial guiding force when it contacts the upper edge of the wear-resistant sleeve 4, which will automatically correct the locking sleeve 2 to the coaxial position with the wear-resistant sleeve 4 and guide it to be put in smoothly. The installation is simpler and more convenient, and the work efficiency is improved.

[0025] Furthermore, the wear-resistant sleeve 4 is made entirely of ceramic material.

[0026] Specifically, the overall hardness of the ceramic is uniform, and there is no transition zone between the hard coating and the soft substrate. This completely eliminates failure states such as ceramic layer peeling and flaking caused by insufficient bonding between the ceramic layer and the substrate or mismatch in thermal expansion coefficients. When resisting extremely abrasive plastics such as glass fiber and mineral powder, the overall ceramic structure has a longer service life.

[0027] Furthermore, the wear-resistant sleeve 4 comprises, from the inside out, a wear-resistant layer 41, a high-temperature resistant layer 42, and a protective layer 43; the high-temperature resistant layer is made of a nickel-based high-temperature alloy, and the protective layer 43 is made of a chromium alloy.

[0028] Specifically, nickel-based superalloys are core materials for aerospace applications. They exhibit high high-temperature strength retention, creep resistance, and oxidation resistance in the 700°C-1000°C range. As the intermediate high-temperature resistant layer 42, it perfectly matches the thermal expansion characteristics of the inner and outer layers. It can buffer the enormous thermal stress caused by the difference in thermal expansion coefficients between the inner and outer layer materials (such as the inner ceramic layer and the outer chromium alloy), preventing interlayer cracking. The chromium alloy protective layer 43 (which can refer to high-chromium tool steel or chromium-based alloy) has high hardness, good wear resistance, and excellent corrosion resistance, protecting the inner core layer.

[0029] Furthermore, a heat insulation ring 6 is provided between the wear-resistant sleeve 4 and the locking sleeve 2, and the heat insulation ring 6 is a PTFE sealing ring.

[0030] Specifically, the heat insulation sealing ring 3 is mainly responsible for axial thermal isolation, stress buffering, and end face sealing; the heat insulation ring 6 in this embodiment is mainly responsible for radial thermal isolation, fitting clearance compensation, and side sealing. The material is specified as polytetrafluoroethylene (PTFE), which has an extremely low coefficient of friction, excellent chemical inertness, a wide operating temperature range (-200°C to +260°C, with short-term higher temperatures) and good elastic memory. This greatly alleviates the risk of high-temperature softening of the locking sleeve 2 material, ensures the structural strength and long-term stability of its threaded connection, and fundamentally protects the core structural components of the mold. In addition, it wraps around the wear-resistant sleeve 4, which can protect the integrity of the outer surface of the wear-resistant sleeve 4, especially its outer protective layer 43, extending the service life of the entire assembly.

[0031] Furthermore, the outer wall of the heat insulation ring 6 is provided with a first inclined surface 61, and the cross-section of the heat insulation ring 6 is a right trapezoidal shape. The side wall of the mounting groove 21 is also provided with a second inclined surface 211, and the cross-section of the mounting groove 21 is a trapezoidal groove. The maximum outer diameter of the heat insulation ring 6 is larger than the maximum inner diameter of the mounting groove 21, and the minimum outer diameter of the heat insulation ring 6 is larger than the minimum inner diameter of the mounting groove 21.

[0032] Specifically, the right-angled trapezoidal cross-section heat insulation ring 6 can be regarded as a flexible wedge, and the trapezoidal groove cross-section mounting groove 21 is its corresponding wedge hole. When the locking sleeve 2 is screwed down, the inclined side wall of the mounting groove 21 will slide relative to the inclined outer side wall of the heat insulation ring 6. Since the maximum / minimum outer diameter of the heat insulation ring 6 is greater than the corresponding inner diameter of the mounting groove 21, this sliding process is actually a continuous and forced radial compression process. The assembly process is smooth and controllable. For the wear-resistant sleeve 4 containing a brittle ceramic layer or hard alloy inside, this gentle, surface contact fastening method can effectively prevent it from breaking or generating micro-cracks due to installation stress.

[0033] Furthermore, the bottom surface of the end cap 1 is recessed inward and a pressing groove 11 is provided. The locking sleeve 2 is disposed in the pressing groove 11. When the end cap 1 is pressed by the locking member, the top surface of the locking sleeve 2 is in close contact with the bottom of the pressing groove 11.

[0034] Specifically, the locking sleeve 2 is threadedly connected to the diverter plate 5 through its own threaded part 23, generating a huge axial tension force to complete the main fixation and sealing. The end cover 1 is fixed to the diverter plate 5 by external locking parts (such as bolts). The pressing groove 11 at its bottom is like a cap covering and pressing the top of the locking sleeve 2, so that the top surface of the locking sleeve 2 is tightly fitted with the bottom of the pressing groove 11. This can apply a constant, additional axial preload to the locking sleeve 2, improve the stability of the locking sleeve 2 and the wear-resistant sleeve 4, and ensure the smooth sliding of the valve needle.

[0035] Furthermore, the end cap 1 is provided with an anti-rotation threaded hole 12, and an anti-rotation bolt 13 is threadedly connected to the anti-rotation threaded hole 12. The bottom surface of the anti-rotation bolt 13 presses against the top surface of the locking sleeve 2.

[0036] Specifically, the anti-rotation bolt 13 is tightened so that the bottom surface of the anti-rotation bolt 13 presses against the top surface of the locking sleeve 2, thereby preventing the locking sleeve 2 from rotating. This effectively prevents any slight rotation of the locking sleeve 2 in the loosening direction, further improving its stability under asymmetrical loads or impacts.

[0037] Other components and operations of the wear-resistant and heat-resistant valve needle sleeve according to the embodiments of this utility model are known to those skilled in the art and will not be described in detail here.

[0038] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0039] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A wear-resistant and heat-resistant valve needle sleeve, characterized in that: Includes end caps, locking sleeves, heat-insulating sealing rings, and wear-resistant sleeves; The locking sleeve and the wear-resistant sleeve are respectively provided with valve pin holes in the vertical direction; The bottom surface of the locking sleeve is recessed inward and has a mounting groove, which communicates with the valve pin hole of the locking sleeve. The wear-resistant sleeve is disposed within the mounting groove; the heat-insulating sealing ring is disposed between the wear-resistant sleeve and the bottom wall of the mounting groove; The inner wall of the valve pin hole of the wear-resistant sleeve is provided with a wear-resistant layer, which is made of ceramic material; The end cap is fixedly installed on the diverter plate, the diverter plate is provided with a positioning groove, and the end cap presses the locking sleeve and the wear-resistant sleeve into the positioning groove by a locking member.

2. The wear-resistant and heat-resistant valve needle sleeve according to claim 1, characterized in that: The locking sleeve includes a wrench part, a threaded part, and a height limiting part. The wrench part is located at the top of the threaded part, and the height limiting part is located at the bottom of the threaded part. The wrench part is shaped like a hexagonal nut. The threaded part has external threads, and the sidewall of the positioning groove has internal threads. The threaded part and the sidewall of the positioning groove are threadedly connected. The height limiting part is annular.

3. The wear-resistant and heat-resistant valve needle sleeve according to claim 2, characterized in that: The edges of the height-limiting section are chamfered.

4. The wear-resistant and heat-resistant valve needle sleeve according to claim 1, characterized in that: The wear-resistant sleeve is made entirely of ceramic material.

5. The wear-resistant and heat-resistant valve needle sleeve according to claim 1, characterized in that: The wear-resistant sleeve comprises, from the inside out, a wear-resistant layer, a high-temperature resistant layer, and a protective layer; the high-temperature resistant layer is made of a nickel-based high-temperature alloy, and the protective layer is made of a chromium alloy.

6. The wear-resistant and heat-resistant valve needle sleeve according to claim 1, characterized in that: A heat insulation ring is also provided between the wear-resistant sleeve and the locking sleeve, and the heat insulation ring is a PTFE sealing ring.

7. The wear-resistant and heat-resistant valve needle sleeve according to claim 6, characterized in that: The outer wall of the heat insulation ring is provided with a first inclined surface, and the cross-section of the heat insulation ring is a right trapezoidal shape. The side wall of the mounting groove is also provided with a second inclined surface, and the cross-section of the mounting groove is a trapezoidal groove. The maximum outer diameter of the heat insulation ring is larger than the maximum inner diameter of the mounting groove, and the minimum outer diameter of the heat insulation ring is larger than the minimum inner diameter of the mounting groove.

8. The wear-resistant and heat-resistant valve needle sleeve according to claim 1, characterized in that: The bottom surface of the end cap is recessed inward and has a pressing groove. The locking sleeve is disposed in the pressing groove. When the end cap is pressed by the locking member, the top surface of the locking sleeve is in close contact with the bottom of the pressing groove.

9. The wear-resistant and heat-resistant valve needle sleeve according to claim 1, characterized in that: The end cap is provided with an anti-rotation threaded hole, and an anti-rotation bolt is threadedly connected to the anti-rotation threaded hole. The bottom surface of the anti-rotation bolt presses against the top surface of the locking sleeve.

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