Hot runner system

Abstract

A hot runner system is disclosed, comprising a nozzle and a manifold disposed abutting the nozzle. An actuator plate is spaced apart from the manifold by a support pad surrounding the lower opening of an actuator bore extending through the actuator plate. A valve pin extends through the support pad and the manifold to the downstream end of the nozzle. A cylinder is received in the actuator bore from the rear side of the actuator plate, and a piston coupled to the valve pin is received in the cylinder from the front end of the cylinder.

Description

Technical Field

[0001] This application relates to a valve-type gate hot runner system, and more particularly, to a plate-mounted valve pin actuator for a valve-type gate hot runner system. Background Technology

[0002] Valve-gate hot runner systems require maintenance to care for the actuators that switch the valve pins between open and closed positions. The actuators typically include piston seals and often additional seals to prevent pressurized fluid leakage. These seals are typically degraded by heat from the hot runner system. To maximize the output of molds equipped with valve-gate hot runner systems, it is desirable to extend the actuator maintenance intervals. Furthermore, during regular maintenance of the hot runner system, it is desirable to perform simple assembly and disassembly of the system to access the actuator seals, as this reduces mold downtime. Summary of the Invention

[0003] One aspect of this application provides a hot runner system comprising: a hot runner plate; a nozzle received in an orifice in the hot runner plate, the nozzle having a nozzle channel for conveying molding material to a corresponding mold cavity; a manifold disposed against the nozzle, the manifold having a manifold channel in fluid communication with the nozzle channel; an actuator plate spaced apart from the manifold, the actuator plate having an actuator bore extending therethrough; a support pad separating the manifold and the actuator plate, the support pad having a front support surface and a rear support surface, the front support surface being disposed against the manifold, the actuator plate being disposed against the rear support surface, the rear support surface surrounding a lower opening of the actuator bore; a valve pin extending through the support pad and the manifold to a downstream end of the nozzle; a cylinder received in the actuator bore from the rear side of the actuator plate; and a piston coupled to the valve pin, the piston being received in the cylinder from the front end of the cylinder.

[0004] The piston can be sized to pass through the actuator bore without being obstructed by the actuator plate.

[0005] The actuator bore may include a stepped portion, against which the front end of the cylinder is mounted.

[0006] The rear end of the cylinder may include a flange.

[0007] The hot runner system may include a sealing member that surrounds the cylinder and is compressed between the flange and the step portion in the actuator bore.

[0008] The flange can protrude from the piston.

[0009] The flange may include at least one extraction hole.

[0010] The flange can extend outward from the cylinder wall and be positioned against the stepped portion in the actuator bore.

[0011] The hot runner system may include a sealing member surrounding the cylinder and compressed between the circumferential wall of the cylinder and the actuator bore.

[0012] The flange can extend rearward from the cylinder wall at an obtuse angle to the cylinder wall and includes an annular sealing surface that is compressed against the cover plate.

[0013] The front end of the cylinder can be axially spaced from the front side of the actuator plate.

[0014] The cylinder may not need to contact the support pad.

[0015] The support pad may include a bushing portion and a spacer portion, the bushing portion including a valve pin hole through which a valve pin extends.

[0016] The bushing and spacer portions can be separate components.

[0017] The actuator plate may include a fluid conduit that intersects the actuator bore on the front side of the piston, the fluid conduit including an outlet that is at least partially unobstructed by the cylinder liner.

[0018] The hot runner system may include a cover plate that is fixed to the actuator plate and closes the rear opening of the actuator bore.

[0019] The cover plate may include a fluid conduit that is in fluid communication with a piston chamber defined by the piston, cylinder liner and cover plate.

[0020] The hot runner system may include a sealing member sandwiched between a cover plate and the rear end of a cylinder, the sealing member surrounding the inlet and outlet of the fluid conduit. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of a portion of a hot runner system with a valve pin actuator according to an embodiment of this application.

[0022] Figure 2 yes Figure 1 Enlarged view of part 2.

[0023] Figure 3 Is with Figure 1 Part 2 is a similar hot runner system, which illustrates a valve pin actuator with a cylinder liner according to another embodiment of this application.

[0024] Figure 4 Is with Figure 1 Part 2 is a similar hot runner system, which illustrates a valve pin actuator with a cylinder liner according to another embodiment of this application.

[0025] Figure 5 Is with Figure 1 Part 2 is a similar hot runner system, which illustrates a valve pin actuator with a cylinder liner according to another embodiment of this application.

[0026] Figure 6 Is with Figure 1 Part 2 is a similar hot runner system, which illustrates a valve pin actuator with a cylinder liner according to another embodiment of this application.

[0027] Figure 7 yes Figure 1 Part 7, in which a hot runner system is assembled and the valve pins of the hot runner system are in the closed position.

[0028] Figure 8 yes Figure 1 Part 7 shows a hot runner system where the cover plate and actuator plate are separated.

[0029] Figure 9 yes Figure 1 Section 7 shows the removal of the actuator cylinder from the actuator plate.

[0030] Figure 10 yes Figure 1 Part 7 shows the separation of the actuator plate from the hot runner plate of the hot runner system.

[0031] Figure 11 yes Figure 1 Part 7 shows the valve pin being removed from the support pad of the hot runner system.

[0032] Figure 12 yes Figure 1 Part 7 shows the cylinders and pistons of the hot runner system being removed from the actuator plate, without the actuator plate being separated from the hot runner plate. Detailed Implementation

[0033] In the following description, "downstream" refers to the general direction in which molding material flows from the injection unit to the mold gate of the mold cavity of the injection molding equipment, and the sequence or characteristics of the components through which molding material flows from the inlet of the injection molding equipment to the mold gate. "Upstream" refers to the opposite direction.

[0034] In the following description, "backward" refers to the direction toward the fixed platform of the molding machine, while "forward" refers to the direction away from the fixed platform of the molding machine.

[0035] In the following description, reference numerals followed by the letter "s" indicate schematically shown parts or features.

[0036] The following description is not intended to be construed as being bound by any express or implied theory.

[0037] Figure 1 This is a cross-sectional view of a portion of a hot runner system 100 according to an embodiment of this application. The hot runner system 100 is used to deliver molding material to a mold cavity 104s, which defines the shape of a molded article 106s formed by the hot runner system 100. The hot runner system 100 includes a manifold 108, a nozzle 109, a support pad 110, a valve pin 112, and an actuator 101. (Actuator 101 is a valve pin actuator.) In operation, the actuator 101 causes the valve pin 112 to switch between a closed position and an open position, in which the valve pin 112 blocks the mold gate 114s leading to the mold cavity 104s to prevent molding material from entering the mold cavity 104s; in the open position, the valve pin 112 disengages from the mold gate 114s to allow molding material to be injected into the mold cavity 104s. Figure 1 In the middle, valve pin 112 is in the closed position.

[0038] Manifold 108 and nozzle 109 are received in housing 115, which is formed by hot runner plate 116 and actuator plate 118 fixed to hot runner plate 116. Manifold 108 is positioned against nozzle 109 and includes manifold passage 120 (partially shown in dashed lines) extending therethrough. Nozzle 109 is located in orifice 124 in hot runner plate 116 and includes nozzle passage 125 in fluid communication with manifold passage 120. In operation, molding material flows through manifold passage 120 and nozzle passage 125 and enters mold cavity 104s via mold gate 114s.

[0039] Continue to refer to Figure 1 The support pad 110 includes a bushing portion 128 and a spacer portion 130. The bushing portion 128 is received in a valve pin passage 132 that extends through the manifold 108. The bushing portion 128 includes a valve pin bore 133 through which a valve pin 112 extends. At least a portion of the valve pin bore 133 is sized to approximate the valve pin 112 to reduce or prevent molding material and / or molding material byproducts from migrating through the valve pin bore 133 to the actuator 101.

[0040] Actuator plate 118 includes an actuator bore 134 extending therethrough, in which actuator 101 is received. In this configuration, actuator 101 can be described as plate-mounted. Actuator plate 118 includes a cooling channel 129 through which cooling fluid circulates to maintain actuator plate 118 and actuator 101 at a suitable operating temperature. Spacer portion 130 covers a portion of manifold 108 and blocks manifold 108 from pressurized fluid used to move valve pin 112 to the open position. Actuator plate 118 is spaced apart from manifold 108 by spacer portion 130. Spacer portion 130 includes a front support surface 135 and a rear support surface 136. Front support surface 135 is positioned against manifold 108 and surrounds valve pin passage 132. Actuator plate 118 is positioned against rear support surface 136, which surrounds the front opening 138 of actuator bore 134, thereby surrounding the front end of actuator bore 134 with support pad 110. The rear end of actuator bore 134 is surrounded by cover plate 139, which is fixed to actuator plate 118 and surrounds the rear opening 140 of actuator bore 134. Figure 1 and Figure 2 In the illustrated embodiment, the support pad 110 is an integral component having a bushing portion 128 and a spacer portion 130.

[0041] refer to Figure 2 , Figure 2 yes Figure 1 A magnified view of part 2 shows that actuator 101 includes cylinder 142 and piston 144. Valve pin 112 is coupled to piston 144 and extends through support pad 110 and manifold 108. Actuator 101 includes: a front chamber 162 defined by piston 144, cylinder 144, actuator bore 134 and support pad 110; and a rear chamber 163 defined by piston 144, cylinder 142 and cover plate 139. Piston 144 is moved to the open position (see also) by directing pressurized fluid to front chamber 162 via open fluid conduit 164. Figure 1 The open fluid conduit 164 extends laterally within the actuator plate 118 and intersects with the actuator bore 134 on the downstream side of the piston 144. Conversely, the piston 144 is moved to the closed position by directing pressurized fluid to the rear piston chamber 163 via the closed fluid conduit 165, which extends within the cover plate 139 and is in fluid communication with the rear chamber 163 via the rear chamber inlet 166. Figure 1 and Figure 2 In the illustrated embodiment, the rear cavity inlet 166 is located at the rear end 152 of the cylinder 142 and is defined by the inner peripheral surface of the inner flange 157.

[0042] Continue to refer to Figure 2Cylinder 142 is mounted in actuator bore 134 from the rear side of actuator plate 118, i.e., through the rear opening 140 of actuator bore 134, while piston 144 is mounted in cylinder 142 from the front opening 145, i.e., through the front opening 146 of cylinder 142. Piston 144 is sized to pass through actuator bore 134 without obstruction by actuator plate 118. In other words, the diameter of actuator bore 134 is larger than the diameter of piston 144 between the rear opening 140 and the front opening 138. In this configuration, piston 144 can pass through actuator bore 134 from either side of actuator plate 118, which facilitates the assembly and disassembly of the hot runner system in various ways to accommodate different types of maintenance of actuator 101.

[0043] Continue to refer to Figure 2 The cylinder 142 is typically sleeve-shaped and includes a cylinder wall 148 having an inner circumferential surface 149 to which the piston 144 slidably engages; and an outer circumferential surface 150 that contacts the actuator bore 134 to facilitate cooling of the actuator 145. The cylinder 142 also includes a flange 151 extending from the cylinder wall 148. The flange 151 increases the surface area of ​​the rear end 152 of the cylinder 142 to accommodate a sealing member 155 compressed between the cylinder 142 and the cover plate 139. The flange 151 includes an outer flange 156 and an inner flange 157. The outer flange 156 extends outward from the cylinder wall 148 and protrudes beyond the actuator plate 118. An inner flange 157 extends inward from the cylinder wall 148 and protrudes from the piston 144 to provide a lip 158 through which the cylinder 142 can engage (e.g., by hand or with a suitable tool) to aid in removal of the cylinder 142 from the actuator bore 134. Figure 1 and Figure 2 In the illustrated embodiment, the front end 145 of the cylinder 142 is positioned against a step portion 160 (facing rearward) in the actuator bore 134. The step portion 160 is rearwardly spaced from the front side of the actuator plate 118 to physically separate the cylinder 142 from the support pad 110, which helps to limit heat transfer from the manifold 108 to the cylinder 142.

[0044] exist Figure 1 and Figure 2 In the illustrated embodiment, the step portion 160 intersects with the open fluid conduit 164. In this configuration, the outlet 168 of the open fluid conduit 164 is partially blocked by the cylinder 142, and the front end 145 of the cylinder 142 is exposed to pressurized fluid when the piston 144 moves to the open position, which helps to reduce the temperature of the cylinder 142.

[0045] Actuator 101 typically includes a piston seal 169, such as an O-ring that slidably engages with an inner circumferential surface 149. The actuator may also be provided with one or more additional sealing members that limit or prevent leakage of pressurized fluid from the front chamber 162 and / or the rear chamber 163.

[0046] exist Figure 1 and Figure 2 In the illustrated embodiment, seal 155 is a rear chamber seal that surrounds the chamber inlet 166 and outlet 170 of the closed fluid conduit 165. Actuator 101 also includes a front chamber seal 172 that surrounds the cylinder wall 148 and is compressed by an outer flange 156 and another stepped portion 175 in actuator bore 134.

[0047] Figure 3 Is with Figure 1 Part 2 is a portion of a similar hot runner system 100a, which illustrates an actuator 101a according to another embodiment of this application. The features and aspects of the current embodiment can be used in conjunction with other embodiments disclosed herein. Figure 3 In the illustrated embodiment, the flange 156a of the cylinder 142 is positioned against a stepped portion 160a (facing rearward) in an actuator bore 134a, which extends through the actuator plate 118a. (Continuing to refer to...) Figure 3 In the illustrated embodiment, the inner flange 157a includes an extraction hole 177a formed therein, into which a tool (not shown) can be inserted to assist in removing the cylinder 142a from the actuator hole 134a. The extraction hole 177a may be threaded to engage with a corresponding threaded tool. Figure 3 In the illustrated embodiment, the extraction hole 177a extends through the thickness of the inner flange portion 157a; however, the extraction hole 177a may also be formed in the outer flange portion 156a. Furthermore, in Figure 3 In the illustrated embodiment, actuator 101a includes a front cavity seal 172a that surrounds an outer flange 156a and is compressed against a portion of an actuator bore 134a extending rearward from a step portion 160a.

[0048] Figure 4 Is with Figure 1 Part 2 is a portion of a similar hot runner system 100b, which illustrates an actuator 101b according to another embodiment of this application. The features and aspects of the current embodiment can be used in conjunction with other embodiments disclosed herein. Figure 4In the illustrated embodiment, the actuator bore 134b extending through the actuator plate 118b includes a stepped portion 160b (facing rearward), against which the front end 145b of the cylinder 142b is positioned. The stepped portion 160b is located behind the outlet 168b of the opening fluid conduit 164b. In this configuration, the outlet 168b is not obstructed by the cylinder 142b. Figure 4 In the illustrated embodiment, the outer peripheral surface 150b of the cylinder 142b extends to the rear end 152b of the cylinder 142b. In other words, the cylinder 142b does not have an outer flange portion. Figure 4 In the illustrated embodiment, the front cavity seal 172b surrounds the outer peripheral surface 150b, and the portion of the actuator hole 134b located behind the stepped portion 160b is compressed.

[0049] Figure 5 Is with Figure 1 Part 2 is a similar hot runner system 100c, which illustrates an actuator 101c according to another embodiment of this application. The features and aspects of the current embodiment can be used in conjunction with other embodiments disclosed herein. Figure 5 In the illustrated embodiment, actuator 101c includes a cylinder 142c with a flange 151c extending rearward from cylinder wall 148c at an obtuse angle α. Instead of a separate sealing member, flange 151c includes an annular sealing surface 182c surrounding a closed cavity inlet 166c of cylinder 142c. When cover plate 139 is secured to actuator plate 118c, flange 151c is compressed, forming a rear cavity seal surrounding outlet 168 of closed fluid conduit 165 and closed cavity inlet 166c. Although flange 151c is shown extending inward from cylinder wall 148c at an obtuse angle, flange 151c may alternatively extend outward from cylinder wall 148c at an obtuse angle (not shown).

[0050] Figure 6 Is with Figure 1 Part 2 is a portion of a similar hot runner system 100d, which illustrates an actuator 101d according to another embodiment of this application. The features and aspects of the current embodiment can be used in conjunction with other embodiments disclosed herein. Figure 6In the illustrated embodiment, the hot runner system 100d includes an actuator 101d having a cylinder 142d with an inner circumferential surface 149d extending axially through it. In other words, the cylinder 142d has no inner flange. In this configuration, the inner circumferential surface 149d can be described as forming a rear port 184d through which a piston 144 can be mounted in the cylinder 142d. In this configuration, the piston 144 can be mounted in the cylinder 142d from either the front end 145d or the rear end 152d. In operation, pressurized fluid is introduced through the rear port 184d into the rear chamber 163d of the actuator 101d. Figure 6 In the illustrated embodiment, actuator 101d includes a rear chamber seal 155d, which is compressed between cylinder wall 148d and cover plate 139, and actuator 101d includes a front chamber seal 172d, which is compressed between cylinder wall 148d and rearward step portion 160d in actuator bore 134d, with cylinder 142d positioned against the rearward step portion 160d.

[0051] Continue to refer to Figure 6 In the illustrated embodiment, the support pad 110d includes a bushing portion 128d and a spacer portion 130d as separate components. The bushing portion 128d is received in a valve pin passage 132 and includes a flange 187d positioned abutting against a manifold 108. The bushing portion 128d extends rearward from the flange 187d and is received in a hole 188d in the spacer 130d, whereby the spacer 130d is positioned on the manifold 108.

[0052] Figures 7 to 12 yes Figure 1 The view of part 7 depicts the disassembly of the hot runner system 100 for maintenance.

[0053] refer to Figure 7 The hot runner system 100 is assembled and the valve pin 112 is in the closed position.

[0054] refer to Figure 8 The cover plate 139 separates rearward from the actuator plate 118 as indicated by arrow R, thereby exposing the rear end 152 of the cylinder 142.

[0055] refer to Figure 9 By engaging the lip 158 with a suitable extraction tool (not shown) and pulling the cylinder 142 in the rearward direction as indicated by arrow R, the cylinder 142 is removed from the actuator hole 134.

[0056] refer to Figure 10The actuator plate 118 separates from the hot runner plate 116, thereby exposing the piston 144. The piston seal 169 is freely accessible to the cylinder 142, which was previously removed from the actuator plate 118 (see [link]). Figure 9 The relevant front cavity seal 172 and rear cavity seal 155 (see...) Figure 9 The same applies.

[0057] refer to Figure 11 On actuator plate 118 ( Figure 11 If the piston 144, valve pin 112 and / or support pad 110 require maintenance after being removed from the hot runner plate 116 (not shown), the valve pin 112 can be removed from the valve pin hole 133 and the support pad 110 can be removed from the valve pin passage 132 without being obstructed by the actuator plate 118.

[0058] refer to Figure 12 The hot runner system 100 also allows the cylinder 142 and piston 144 to be removed from the actuator bore 134 without separating the actuator plate 118 from the hot runner plate 116. This is achieved by removing the cover plate 139 ( Figure 12 After separating from the actuator plate 118 (not shown), the tool 191 is secured to the piston 144, for example, via a threaded connection between the two. With the tool 191 secured to the piston 144, the tool 191 moves backward as indicated by arrow R, pulling the piston 144 backward. When the piston 144 contacts the inner flange 157, as... Figure 12 As shown, further rearward displacement of tool 191 pulls both piston 144 and cylinder 142 backward to remove both cylinder 142 and piston 144 from actuator bore 134.

[0059] While various embodiments have been described above, they are presented by way of illustration and example only, and not as limitations. Therefore, this application should not be limited to any of the above embodiments, but should be defined solely by the appended claims and their equivalents.

Claims

1. A hot runner system, comprising: Hot runner plate; A nozzle, which is received in the orifice of the hot runner plate, has a nozzle channel for conveying molding material into a corresponding mold cavity; A manifold, wherein the manifold is disposed against the nozzle, and the manifold has a manifold passage in fluid communication with the nozzle passage; An actuator plate, located upstream of the hot runner plate and spaced apart from the manifold, the actuator plate having an actuator hole extending therethrough; A support pad that separates the manifold and the actuator plate, the support pad having a front support surface that is positioned against the manifold; and a rear support surface, wherein the actuator plate is mounted against the rear support surface, and the rear support surface surrounds the lower opening of the actuator hole; A valve pin, which passes through the support pad and the manifold and extends to the downstream end of the nozzle; A cylinder, which is received in the actuator bore from the rear side of the actuator plate; as well as A piston, which is connected to the valve pin, is received in the cylinder from the front end of the cylinder; The actuator plate includes a fluid conduit that intersects the actuator bore on the front side of the piston, and the fluid conduit includes an outlet that is at least partially obstructed by the cylinder.

2. The hot runner system according to claim 1, wherein, The piston is sized to pass through the actuator bore without being obstructed by the actuator plate.

3. The hot runner system according to claim 1, wherein, The actuator bore includes a stepped portion, and the front end of the cylinder is positioned against the stepped portion.

4. The hot runner system according to claim 1, wherein, The rear end of the cylinder includes a flange.

5. The hot runner system of claim 4 further includes a sealing member surrounding the cylinder and compressed between the flange and the step portion in the actuator bore.

6. The hot runner system according to claim 4, wherein, The flange protrudes from the piston.

7. The hot runner system according to claim 4, wherein, The flange includes at least one extraction hole.

8. The hot runner system according to claim 4, wherein, The flange extends outward from the wall of the cylinder and is positioned against the stepped portion in the actuator bore.

9. The hot runner system of claim 1 further includes a sealing member surrounding the cylinder and compressed between the circumferential wall of the cylinder and the actuator bore.

10. The hot runner system according to claim 4, wherein, The flange extends rearward from the wall of the cylinder at an obtuse angle to the wall of the cylinder, and the flange includes an annular sealing surface that is compressed against the cover plate.

11. The hot runner system according to claim 1, wherein, The front end of the cylinder is axially spaced from the front side of the actuator plate.

12. The hot runner system according to claim 1, wherein, The cylinder does not contact the support pad.

13. The hot runner system according to claim 1, wherein, The support pad includes a bushing portion and a spacer portion, the bushing portion including a valve pin hole through which the valve pin extends.

14. The hot runner system according to claim 13, wherein, The bushing portion and the spacer portion are separate components.

15. The hot runner system according to claim 1, further comprising a cover plate fixed to the actuator plate and closing the rear opening of the actuator hole.

16. The hot runner system according to claim 15, wherein, The cover plate includes the fluid conduit, which is in fluid communication with a piston chamber defined by the piston, the cylinder, and the cover plate.

17. The hot runner system of claim 16, further comprising a sealing member sandwiched between the cover plate and the rear end of the cylinder, the sealing member surrounding the inlet and outlet of the fluid conduit.

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