A valve used to control the flow of molten material from the gate to the mold cavity

Abstract

The present invention belongs to the field of injection molding technology, and particularly relates to a valve for controlling the flow of molten material injected from a gate into a mold cavity, which solves the problem of poor flow control effect of molten material and poor quality of molded products. The valve for controlling the flow of molten material injected from a gate into a mold cavity comprises a valve body, the valve body is provided with a gate arranged along a first axis, the valve body is also provided with a valve movable hole arranged along a second axis and the inner end of which is connected to the gate, the valve movable hole is provided with a valve core that can move along the second axis to change the width of the gate channel, the valve core is connected to a driving member that can move along a third axis, and a slope is provided between the driving member and the valve core that can push the valve core to move along its second axis when the driving member moves along its third axis. The effect of stably controlling the output flow of molten material is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding, and in particular relates to a valve for controlling the flow of molten material injected from a gate into a mold cavity. Background Art

[0002] During injection molding, the flow control of the molten material is achieved by a gate valve. The prior art is to control the flow of the molten material leaving the gate toward the mold cavity by a valve needle or shutter, which can move back and forth linearly according to the flow of the molten material. However, the presence and alternating movement of the valve needle increases the disturbance of the flow by creating areas of accumulation and stagnation of the material, so that, for example, the color change operation of the injected material requires multiple cleaning injections, resulting in a large amount of material waste.

[0003] As in the EP520345 patent, the angled valve pin has the defect of pushing the material against the inner surface of the passage, further compressing it to the outlet. This crushing effect causes defects in the final part.

[0004] In an attempt to solve this problem, the valve needle is replaced with a gate valve located at the material outlet gate. This solution is shown in the EP1409222 patent (Figure 13), which is adopted to simultaneously control the opening and closing of multiple injectors (nozzles) placed in a line and controlled by a single actuator.

[0005] However, a single moving gate knife involves crushing material towards the periphery of the gate orifice, which is at a lower temperature, thereby causing defects in the molded product.

[0006] A better solution, as described in the EP1064138 patent, uses two opposing gate valves whose closing point is in the center of the channel, because the temperature is higher there. However, the EP1064138 patent provides two flat gate knives operated by a single actuator located on the far periphery of the mold, with considerable complexity in terms of manipulation and imprecise control of the position of the gate knives. The installation is also complex and expensive, because the gate knives are close to the gate (the outlet hole of the plastic material) and therefore close to the cavity of the mold, requiring a low containment thickness, i.e. a very durable and expensive material. However, despite the efforts made, it is still impossible to eliminate the traces (small cylindrical protrusions) left by this solution on the molded part. Summary of the invention

[0007] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and to propose a valve for controlling the flow of molten material injected from the gate to the mold cavity, for improving the activity control of the valve core, and for improving the performance and / or characteristics of the molten material output by the valve.

[0008] In order to achieve the purpose of the invention, the following technical solutions can be used: A valve for controlling the flow of molten material injected from a gate into a mold cavity, comprising a valve body, the valve body being provided with a gate arranged along a first axis, the valve body being further provided with a valve movable hole arranged along a second axis and the inner end of which is connected to the gate, the valve movable hole being provided with a valve core which can move along the second axis to change the width of the gate channel, the valve core being connected to a driving member which can move along a third axis, and an inclined surface being provided between the driving member and the valve core which can push the valve core to move along its second axis when the driving member moves along its third axis.

[0009] The valve body of the present invention is provided with a gate, and a channel for the flow of molten material is formed in the gate. The valve movable hole is staggered and connected with the gate. The valve movable hole is in a straight line, and a valve core is slidably connected therein. The front end of the valve core can be inserted horizontally into the flow channel of the gate to limit the flow to control the output rate of the molten material, and can even completely block the channel to stop the material output. The driving member can move forward and backward along the third axis. The valve core and the driving member are coupled by an inclined surface, and the linear displacement of the driving member is converted into the displacement of the valve core. The inclined surface has a transmission effect. Moreover, the driving member and the valve core are in good contact through the inclined surface, which increases the contact area, so that the pressure of the molten material is distributed over a larger area, reducing the possibility of the contact surface being crushed, preventing jamming or wear, and having high stability. At the same time, the requirements for manufacturing materials are also reduced, and materials with lower performance and less hardness can be selected. The material is generally low in price, which is conducive to the control of processing costs. In addition, under the premise of meeting the corresponding transmission requirements, the setting position, inclination angle and length of the inclined surface can be adjusted accordingly, that is, the relative position and angle of the driving part and the valve core can be adjusted, so that the driving part can be moved away from the key area of ​​the mold, which is conducive to the compactness of the overall layout of the system.

[0010] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the first axis is orthogonal to the second axis, or the first axis intersects the second axis at a point.

[0011] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the second axis is orthogonal to the third axis, or the second axis intersects the third axis at one point.

[0012] The second and third axes form a plane, and the plane is parallel, coplanar or orthogonal to the first axis.

[0013] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the valve core includes a flow control rod, which is arranged in the movable hole of the valve and moves along its axial direction, and the inner end can extend into the gate to adjust the flow.

[0014] The valve core realizes corresponding flow control through the movement of the flow control rod. The flow control rod is a straight rod that can slide axially in the valve activity hole. The free end of the inner end can be staggered into the gate to achieve the flow limiting effect.

[0015] In the above-mentioned valve for controlling the flow of molten material injected from a gate into a mold cavity, the inclined surface is arranged in a groove of the driving member and / or the valve core.

[0016] A groove is arranged at the rear end of the valve core or on the side of the driving member near the valve core, and a slope is formed on the side of the groove. The driving member and the valve core respectively include corresponding slopes, and these slopes are in sliding contact with each other. Of course, the extension direction of the slope is obliquely intersected with the length direction of the valve core and the moving direction of the driving member.

[0017] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, a limiting structure capable of preventing the driving member and the valve core from being separated when the driving member and the valve core are slidably connected is provided in the groove.

[0018] The limiting structure is used to limit the connection part when the valve core moves relative to the driving member, to ensure the stable connection between the two, and at the same time to limit the relative movement path of the two.

[0019] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the limit structure includes a travel limit groove arranged on the driving member and communicating with the groove, the axis of the travel limit groove and the axis of the inclined plane are parallel to each other, a slide rod is arranged in the travel limit groove, and the slide rod is connected to the valve core; Alternatively, the limiting structure comprises a slide groove arranged in the groove and located at at least one side, the axis of the slide groove and the axis of the inclined plane are parallel to each other, and a sliding block cooperating with the slide groove is provided on the valve core.

[0020] The end of the valve core is inserted into the groove of the driving member, and a sliding rod is inserted into the through hole of the end. The heads of the two ends of the sliding rod protrude from the upper and lower end surfaces of the valve core. The heads are slidably connected in two slide grooves. The slide groove is opened on the driving member, and the groove is located between the two slide grooves. The groove extends along the bisector of the angle between the feed direction of the valve core and the forward direction of the driving member. Of course, the bisector does not necessarily have to divide the angle equally. As another scheme, the limiting structure can also be realized by a slider and a corresponding slide groove on the valve core. The slider is set at the end of the valve core to form an L-shaped or T-shaped structure. The inner end of the groove of the driving member is provided with a slide groove. The slide groove extends horizontally through the inclined surface direction and protrudes upward and / or downward to form an L-shaped or T-shaped shape adapted to the slider. The plane of the side of the slider and the plane of the side of the slide groove slide in contact to limit the rotation and ensure the translational movement of the valve core.

[0021] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the valve body is also provided with a plurality of valve movable holes arranged along the second axis and the inner ends of which are connected to the gate. The valve core is respectively provided in each valve movable hole, and the valve core is connected to respective driving members. The plurality of driving members are connected to linkage members that can enable the driving members to move synchronously back and forth along the axis.

[0022] A plurality of valve movable holes respectively connected to the gates can be arranged on the valve body, and a corresponding valve core is slidably connected in each valve movable hole, and each valve core is connected to a corresponding driving member, and the moving paths of the driving members are parallel to each other, and the synchronous movement of the driving members can be controlled by a linkage member, and the valve cores move towards or away from each other, and the molten material flows between the relative valve cores, so that the accumulation area of ​​the molten material is relatively uniform in the circumferential direction, and when the gate needs to be blocked, the valve core is docked in the middle of the gate, shortening the moving path length of a single valve core. Specifically, the linkage member includes a linkage bracket with a center hole, the valve body is inserted into the center hole, and the driving members are circumferentially distributed on the outside of the linkage bracket.

[0023] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the gate is also provided with a withdrawal hole located on the opposite side of the valve movable hole, which can allow the inner end of the valve core to pass through the gate and enter the withdrawal hole for interception.

[0024] A withdrawal hole is provided on the inner wall of the gate, and the withdrawal hole is located on the straight line where the moving path of the valve core is located. After the valve core is inserted, the front end of the free end of the valve core is inserted into the withdrawal hole to support and position the front end, thereby improving the bearing capacity of the free end of the valve core on the molten material.

[0025] In the above-mentioned valve for controlling the flow of molten material injected from the gate into the mold cavity, the inclined surface is replaced by a curved surface. Of course, the travel limit groove is also in a corresponding arc shape.

[0026] Compared with the prior art, the present invention mainly has the following advantages: 1. The valve body is provided with a gate, and the front end of the valve core can be inserted horizontally into the gate to limit the flow rate to control the output rate of the molten material, and even the channel can be completely blocked to stop the material output. The valve core and the driver are coupled by an inclined surface to convert the linear displacement of the driver into the displacement of the valve core. In addition, the driver and the valve core are in good contact through the inclined surface, which increases the contact area, so that the pressure of the molten material is distributed over a larger area, reducing the possibility of the contact surface being crushed, preventing jamming or wear, and having high stability. At the same time, it also reduces the requirements for manufacturing materials, and can choose materials with lower performance and less hardness. This material is generally cheaper, which is conducive to the control of processing costs.

[0027] 2. On the premise of meeting the corresponding transmission requirements, the setting position, inclination angle and length of the inclined plane can be adjusted accordingly, that is, the relative position and angle of the driving part and the valve core can be adjusted, so that the driving part can be moved away from the key area of ​​the mold, which is conducive to the compactness of the overall layout of the system.

[0028] 3. The limiting structure is used to limit the connection part when the valve core moves relative to the driving member, ensuring the stable connection between the two and limiting the relative movement path of the two.

[0029] 4. A plurality of valve movable holes connected to the gates respectively can be arranged on the valve body, a corresponding valve core is slidably connected in each valve movable hole, each valve core is connected to a corresponding driving member, the moving paths of the driving members are parallel to each other, and the synchronous movement of the driving members can be controlled by a linkage member, the valve cores move towards or away from each other, and the molten material flows between the relative valve cores, so that the accumulation area of ​​the molten material is relatively uniform in the circumferential direction, and when the gate needs to be blocked, the valve core is docked in the middle of the gate, shortening the moving path length of a single valve core.

[0030] 5. A withdrawal hole is provided on the inner wall of the gate. After the valve core is inserted, the front end of the free end is inserted into the withdrawal hole to achieve support and positioning of the front end, thereby improving the bearing capacity of the free end of the valve core on the molten material. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the overall cross section and an enlarged diagram of the details of the corresponding position provided by the present invention (Example 1); Figure 2 1 is a schematic top view of the gate provided by the present invention in two states: open and closed (Example 1); Figure 3 1 is a schematic diagram of the structure of the driving member and the flow control rod provided by the present invention (Example 1); Figure 4 Schematic diagram of the separation of the driving member and the flow control rod provided by the present invention (Example 1); Figure 5 is a schematic diagram of the overall cross section and an enlarged diagram of the details of the corresponding position provided by the present invention (Example 2); Figure 6 is a schematic diagram of the structure of the driving member and the flow control rod provided by the present invention (Example 2); Figure 7 Schematic diagram of the separation of the driving member and the flow control rod provided by the present invention (Example 2); Figure 8 is a schematic diagram of the overall cross section and an enlarged diagram of the details of the corresponding position provided by the present invention (Example 3); Fig. 9 It is a schematic diagram of the structure of the linkage member and the valve core provided by the present invention (Example 3).

[0032] In the figure, valve body 1, first axis 2, gate 3, second axis 4, valve movable hole 5, valve core 6, third axis 7, driving member 8, inclined surface 9, flow control rod 10, groove 11, limit structure 12, stroke limit groove 13, slide rod 14, slide groove 15, slider 16, linkage member 17, retreat hole 18, mold cavity 19, syringe 20, main plate 21, hollow body 22, axial cavity 23, gate insert 24, mounting cavity 25, pin hole 26, fourth axis 27, narrow slot 28, center hole 29, linkage bracket 30. DETAILED DESCRIPTION

[0033] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0034] Example 1 Specific implementation examples Figure 1-4 As shown, Figure 1 The tip of an injector 20 for injecting molten material into the mold cavity 19 is shown. The injector 20 is mounted in one or more body plates 21 constituting the mold and is fixed to the plate body of the mold for distributing molten material. The injector 20 comprises an innermost hollow body 22 in which an axial cavity 23 extending along the first axis 2 is formed, which is also extremely symmetrical to the tip of the injector 20, which rests on a gate insert 24 having an orifice forming a gate 3, from which the molten material can flow into the gate 3.

[0035] like Figure 1 As shown, a valve movable hole 5 is provided on the gate insert 24, and a flow control rod 10 of a valve core 6 is provided in the valve movable hole 5. The inner end of the flow control rod 10 slides freely in the valve movable hole 5, and the outer end is connected to the driving member 8. The driving member 8 is movably installed in the installation cavity 25 of the gate insert 24, and can move along the third axis 7. The second axis 7 where the installation cavity 2 of this embodiment is located is perpendicular to the first axis 2 where the gate 3 is located. The outer end of the flow control rod 10 is located in the groove 11 of the driving member 8. A pin hole 26 is also provided on the outer end, and a slide rod 14 is penetrated in a tight fit on the pin hole 26. The slide rod 14 is exposed on the upper and lower end surfaces of the outer end of the flow control rod 10 to form a head.

[0036] like Figure 3 , 4As shown, the heads at both ends of the slide bar 14 are slidably engaged in the travel limit groove 13 of the driving member 8, and the travel limit groove 13 is parallel to the inner side wall of the groove 11. The groove 11 can be entered from the outside through the narrow slot 28 and extends along the fourth axis 27. The fourth axis 27 of this embodiment is located on the bisector of the second axis 4 and the third axis 7. When the driving member 8 translates along the third axis 7, the groove 11 translates and pushes the slide bar 14 to move along the inclined surface 9 of the groove 11, and the slide bar 14 then pushes the flow control rod 10 to move along the second axis 4 in the valve activity hole 5. The effect of the groove 11 converting the linear displacement of the driving member 8 into a proportional linear displacement of the flow control rod 10 is achieved. The movement of the flow control rod 10 makes its front end extend into the gate 3, which can realize the control of the switch degree of the gate 3 from fully open to fully closed. Of course, it can also stay in the middle position to maintain the corresponding flow. In this embodiment, the second axis 4 and the third axis 7 are vertically arranged, and of course, they can also be acute angles or obtuse angles.

[0037] As an optimization of this embodiment, a withdrawal hole 18 is further provided in the gate 3 on the side opposite to the valve movable hole 5, and the inner end of the flow control rod 10 passes through the gate 3 and enters the withdrawal hole 18 to intercept the flow, thereby achieving support positioning of the front end and improving the bearing capacity of the free end of the valve core 6 for the molten material.

[0038] Example 2 The specific working principle of this embodiment is substantially the same as that of Embodiment 1, except for the specific structure of the transmission between the valve core 6 and the driving member 8 .

[0039] Specific implementation examples Figure 5-7 As shown, a vertically protruding square slider 16 is provided on the upper and lower end surfaces of the rear end of the flow control rod 10, and a corresponding slide groove 15 is provided on the inner side of the groove 11 of the driving member 8, and the slide groove 15 runs through the edge horizontally along the fourth axis 27. The top and bottom surfaces of the groove 11 are parallel to each other, and a slide groove 15 is provided between the inclined surface 9 on the rear side and the top and bottom surfaces, forming a T-shaped structure matching the slider 16, and the slider 16 slides in the slide groove 15, and planes are provided on the upper and lower sides of the rear end of the flow control rod 10, and the rear end slides between the top and bottom surfaces of the groove 11. Of course, the angle between the front side surface of the slider 16 and the flow control rod 10 is complementary to the angle between the inclined surface 9 and the moving direction of the driving member 8, so as to ensure the translational movement of the flow control rod.

[0040] like Figure 5 As shown, at this time, the driving member 8 is installed in the installation cavity 25 of the gate insert 24, and the cavity is parallel to the axial cavity 23, and the driving member 8 moves axially in the installation cavity 25.

[0041] Example 3 The specific working principle of this embodiment is basically the same as that of Embodiment 1, except for the number of sets of valve core 6 and driving member 8 .

[0042] Specific implementation examples Figure 8 , 9 As shown, the valve body 1 is also provided with a plurality of valve movable holes 5 which are arranged along the second axis 4 and the inner ends of which are connected to the gate 3. A valve core 6 is respectively provided in each valve movable hole 5. The valve core 6 is connected to a respective driving member 8. The plurality of driving members 8 are connected to a linkage member 17 which can enable the driving member 8 to move synchronously back and forth along the axis.

[0043] Specifically, a plurality of valve movable holes 5 respectively connected to the gate 3 can be provided on the valve body 1, and a corresponding valve core 6 is slidably connected in each valve movable hole 5, and each valve core 6 is connected to a corresponding driving member 8, and the moving paths of each driving member 8 are parallel to each other, and the synchronous movement of each driving member 8 can be controlled by the linkage member 17, and each valve core 6 moves toward or away from each other, and the molten material flows between the relative valve cores 6, so that the accumulation area of ​​the molten material is relatively uniform in the circumferential direction, and when the gate 3 needs to be blocked, the valve core 6 is docked in the middle of the gate 3, shortening the moving path length of a single valve core 6. Specifically, the linkage member 17 includes a linkage bracket 30 with a center hole 29, and the valve body 1 is inserted into the center hole 29 thereof, and the driving members 8 are circumferentially distributed outside the linkage bracket 30. The linkage bracket 30 is installed around the syringe 20, and the syringe 20 is penetrated by the center hole 29 and can slide axially.

[0044] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A valve for controlling the flow of molten material injected from a gate into a mold cavity, characterized in that: The invention comprises a valve body (1), wherein the valve body (1) is provided with a gate (3) arranged along a first axis (2), and the valve body (1) is also provided with a valve movable hole (5) arranged along a second axis (4) and the inner end of which is connected to the gate (3), wherein a valve core (6) is arranged in the valve movable hole (5) and can move along the second axis (4) to change the width of the gate (3) channel, and the valve core (6) is connected to a driving member (8) that can move along a third axis (7), and an inclined surface (9) is arranged between the driving member (8) and the valve core (6) and can push the valve core (6) to move along the second axis (4) when the driving member (8) moves along the third axis (7).

2. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to claim 1, characterized in that: The first axis (2) is orthogonal to the second axis (4), Alternatively, the first axis (2) and the second axis (4) intersect at one point.

3. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to claim 2, characterized in that: The second axis (4) is orthogonal to the third axis (7), Alternatively, the second axis (4) and the third axis (7) intersect at one point.

4. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to claim 3, characterized in that: The valve core (6) comprises a flow control rod (10), which is arranged in the valve movable hole (5) and moves along its axial direction, and the inner end of the flow control rod (10) can extend into the gate (3) to adjust the flow.

5. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to claim 4, characterized in that: The inclined surface (9) is arranged in a groove (11) of the driving member (8) and / or the valve core (6).

6. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to claim 5, characterized in that: The groove (11) is provided with a limiting structure (12) capable of preventing the driving member (8) and the valve core (6) from being separated when they are slidably connected.

7. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to claim 6, characterized in that: The limiting structure (12) comprises a travel limiting groove (13) arranged on the driving member (8) and connected to the groove (11), the axis of the travel limiting groove (13) and the axis of the inclined surface (9) being parallel to each other, a sliding rod (14) being arranged in the travel limiting groove (13), and the sliding rod (14) being connected to the valve core (6); Alternatively, the limiting structure (12) comprises a slide groove (15) arranged in the groove (11) and located on at least one side, the axis of the slide groove (15) and the axis of the inclined surface (9) are parallel to each other, and the valve core (6) is provided with a slider (16) that cooperates with the slide groove (15).

8. A valve for controlling the flow of molten material injected from a gate into a mold cavity according to any one of claims 1 to 7, characterized in that: The valve body (1) is further provided with a plurality of valve movable holes (5) arranged along the second axis (4) and having inner ends connected to the gate (3). A valve core (6) is respectively arranged in each valve movable hole (5). The valve core (6) is connected to a respective driving member (8). The plurality of driving members (8) are connected to a linkage member (17) capable of causing the driving member (8) to move synchronously forward and backward along the axis.

9. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to any one of claims 1 to 7, characterized in that: The gate (3) is also provided with a retreat hole (18) located on the side opposite to the valve movable hole (5), so that the inner end of the valve core (6) can pass through the gate (3) and enter the retreat hole (18) to intercept the flow.

10. The valve for controlling the flow of molten material injected from a gate into a mold cavity according to any one of claims 1 to 7, characterized in that: The inclined surface (9) is replaced by a curved surface.

Images