Shut-off nozzle test device and test method

Abstract

To provide a shut-off nozzle testing device which does not require an injection molder for testing.SOLUTION: A test device (1) provided herein comprises a cylinder (7) for receiving a test fluid therein, and a plunger (11) provided in the cylinder (7) to apply pressure to the test fluid. A shut-off nozzle (2) to be tested is attached to the cylinder (7). When pressured by the plunger (11), the test fluid is supplied to the shut-off nozzle (2) under test. The shut-off nozzle (2) can thus be tested.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a testing device for testing whether a shut-off nozzle has the required performance, and a testing method for testing whether a shut-off nozzle has the required performance. [Background technology]

[0002] A shut-off nozzle installed in the injection unit of an injection molding machine has a valve structure that opens and closes the flow path of the injection material in the injection nozzle, preventing so-called dripping. There are various types of shut-off nozzles, but the shut-off nozzle described in Patent Document 1, for example, is configured as follows: This type of shut-off nozzle consists of a nozzle portion and a needle valve disposed at an angle relative to the nozzle portion. The nozzle portion has an oblique hole, i.e., a needle hole, that extends from the outer peripheral surface of the nozzle portion to the injection flow path within the nozzle portion. A needle valve is inserted into this needle hole so that it can move back and forth. When the needle valve is advanced, the injection flow path is closed, and when it is retracted, the injection flow path is opened. In other words, the valve structure is composed of a needle valve. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 3-274125 Summary of the Invention [Problem to be solved by the invention]

[0004] There are various types of shut-off nozzles other than those described above, but all of them have a valve structure that opens and closes the injection flow path. However, before shipping a manufactured shut-off nozzle, it must be tested to ensure that it meets the required performance. First, it is necessary to test whether the valve structure seals properly. That is, it is necessary to test whether injection material leaks from the shut-off nozzle's injection port when the injection flow path is closed by the valve structure. Next, in the case of the shut-off nozzle of the type described in Patent Document 1, it is necessary to test whether injection material leaks from the needle hole. There is a small gap between the needle hole and the needle valve, allowing the needle valve to move smoothly forward and backward. However, if this gap is too large, injection material will leak.

[0005] Shut-off nozzle testing is performed using a test injection molding machine. That is, the test shut-off nozzle is attached to the test injection molding machine. Then, actual injection operations and other processes are performed to evaluate performance. However, in order to perform the testing, a test injection molding machine must be prepared, which poses problems of increased cost and space requirements.

[0006] The present disclosure provides a shut-off nozzle testing device and a shut-off nozzle testing method that do not require an injection molding machine for testing.

[0007] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0008] The present disclosure is directed to a shut-off nozzle that includes a nozzle body in which an injection flow path is formed and a valve structure that opens and closes the injection flow path, and is configured as a testing device for testing the shut-off nozzle. However, it is configured as a test device for a shut-off nozzle that is different from the injection device of the injection molding machine.The test device includes a cylinder for holding a test fluid and a plunger that is placed in the cylinder and is adapted to pressurize the test fluid. The shut-off nozzle to be tested is adapted to be attached to the cylinder. When the test fluid is pressurized by the plunger, it is supplied to the shut-off nozzle to be tested. Testing of the shut-off nozzle can be performed. In the test device, the lower portion of the shut-off nozzle is covered with a member that prevents the test fluid from splashing to the surrounding area. [Effects of the Invention]

[0009] The present disclosure allows testing of shut-off nozzles without using a test injection molding machine. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a front cross-sectional view of a shut-off nozzle and a testing device for the shut-off nozzle according to the first embodiment of the present invention. [Figure 2A] 3 is a flowchart showing a method for testing a shut-off nozzle according to the present embodiment. [Figure 2B] 3 is a flowchart showing a method for testing a shut-off nozzle according to the present embodiment. [Figure 3] FIG. 10 is a front cross-sectional view of a testing device for a shut-off nozzle according to a second embodiment of the present invention and the shut-off nozzle. [Figure 4A] FIG. 10 is a cross-sectional side view showing a flow path resistor provided in a testing device for a shut-off nozzle according to a second embodiment of the present invention. [Figure 4B] 4B is a front cross-sectional view of a flow path resistor provided in a testing device for a shut-off nozzle according to a second embodiment of the present invention, taken along line XX in FIG. 4A. FIG. [Figure 4C] FIG. 10 is a front cross-sectional view showing a resin supplying device provided in a testing device for a shut-off nozzle according to a third embodiment of the present invention. [Figure 5] 1 is a front cross-sectional view showing a part of a testing device for a shut-off nozzle according to an embodiment of the present invention and a shut-off nozzle equipped with a rotary valve. [Figure 6] 1 is a front cross-sectional view showing a part of a testing device for a shut-off nozzle according to an embodiment of the present invention and a shut-off nozzle equipped with a needle valve. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. For clarity of explanation, the following description and drawings have been simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary. Furthermore, hatching has been omitted in some areas to avoid cluttering the drawings.

[0012] The present embodiment will be described. First Embodiment <Test equipment> 1, the shut-off nozzle testing device 1 according to this embodiment is configured to have a shut-off nozzle 2 to be tested attached in an upright position, and is compact with a relatively small installation space. As will be explained in detail later, there are various types of shut-off nozzles 2, and the testing device 1 according to this embodiment is capable of testing a plurality of types of shut-off nozzles 2.

[0013] The test device 1 is designed to conduct a test by supplying a test fluid to a shut-off nozzle 2, and the lower part of the nozzle is covered by a housing 4 to prevent the test fluid from scattering around. A pan, or liquid reservoir 6, for receiving and storing the test fluid is provided on the bottom of the housing 4.

[0014] A cylindrical support 5 is fixedly mounted inside the housing 4. A cylinder 7, which holds the test fluid, is placed inside the support 5. A nozzle mounting member 9, fixed by bolts 8, 8, ..., is mounted at the tip, or bottom, of the support 5. The shut-off nozzle 2 to be tested, the structure of which will be explained later, is fixed to the support 5 and the cylinder 7 by this nozzle mounting member 9. When the shut-off nozzle 2 to be tested is fixed, its rear end surface is in liquid-tight contact with the bottom end surface of the cylinder 7. As will be explained later, the test fluid held in the cylinder 7 is supplied to the shut-off nozzle 2 without leaking out even when pressurized.

[0015] A plunger 11 that pressurizes the test fluid and pushes it out is placed in the cylinder 7. A drive cylinder unit 13 that drives the plunger 11 is provided on the top of the cylinder 7. The drive cylinder unit 13 may be driven by hydraulic pressure, but in this embodiment it is driven by compressed air from an air supply source 14. The drive cylinder unit 13 is provided with limit switches 15, 15 that detect the piston 16, so that the position of the plunger 11 is indirectly detected.

[0016] The support 5 and the cylinder 7 have fluid supply holes 17 that extend from their sides to the bore of the cylinder 7. A plug 18 is attached to the outlet of the fluid supply hole 17. This plug 18 is removed, and a fluid supply pipe 20 is connected to the fluid supply hole 17 as shown by the dotted line in Figure 1. The test fluid can then be supplied through a funnel 21 to fill the cylinder 7 with the test fluid. After filling, the fluid supply pipe 20 is removed and the plug 18 is closed. This prevents the test fluid from spraying out of the fluid supply hole 17 when the test fluid is pressurized by the plunger 11. The fluid supply pipe 20 may be permanently connected to the fluid supply hole 17. In this case, when pressurizing the test fluid with the plunger 11, the plunger 11 must be slowly advanced until the tip of the plunger 11 passes the fluid supply hole 17 before pressure is applied.

[0017] A bracket 23 is provided on one side of the housing 4, and a needle valve drive piston cylinder unit 24 is provided on this bracket 23. The needle valve drive piston cylinder unit 24 is driven by a valve drive air supply source 25. The needle valve drive piston cylinder unit 24 may be driven hydraulically, or may be driven by the air supply source 14 for driving the drive cylinder unit 13. However, in this embodiment, the valve drive air supply source 25 is provided separately. An opening 26 is provided in part of the housing 4 to accommodate the needle valve drive piston cylinder unit 24.

[0018] <Shut-off nozzle under test> The shut-off nozzle 2 to be tested will now be described. The shut-off nozzle 2 is composed of a nozzle body 28 and a needle valve 29. The nozzle body 28 has an injection passage 31 formed along its axis, through which the injection material flows, and an outlet at the tip of the nozzle body 28 serves as an injection port 32. A needle hole 33 is drilled in the nozzle body 28 from its outer periphery at an angle to the axial direction, reaching the injection passage 31. The needle valve 29 is inserted into this needle hole 33 so that it can move back and forth. In other words, in the shut-off nozzle 2 to be tested, the needle valve 29 is disposed at an angle to the nozzle body 28. When the needle valve 29 is advanced, the injection passage 31 is closed. When the needle valve 29 is retracted, the injection passage 31 is opened. In other words, the needle valve 29 has a valve structure that opens and closes the injection passage of the shut-off nozzle 2.

[0019] The rear end of the needle valve 29 protrudes outward from the opening 26 of the housing 4 and is connected to a needle valve drive piston cylinder unit 24. The needle valve drive piston cylinder unit 24 serves as a valve drive means for driving the needle valve 29 of the shut-off nozzle 2, i.e., the valve structure.

[0020] <Exam preparation stage> A method for testing a shut-off nozzle 2 using the shut-off nozzle testing device 1 according to this embodiment will be described. First, the preparation stage will be described. A test fluid is selected. The test fluid is selected from fluids with a viscosity similar to that of molten resin. For example, grease, lubricating oil, or mustard paste can be selected. Such test fluids can be tested at room temperature, making them safe and cost-effective because they do not require heating with a heater. The selected test fluid is filled into the cylinder 7. That is, as described above, the stopper 18 is removed, and the test fluid is filled into the cylinder 7 using the funnel 21 and fluid supply pipe 20. The fluid supply pipe 20 is removed from the fluid supply hole 17, and the stopper 18 is closed. This completes the preparation stage.

[0021] <Sealing performance test> A test is performed to determine whether the valve structure can normally close the injection flow path 31. As shown in FIG. 2A, a closing process (step S01) is performed. The needle valve drive piston cylinder unit 24 (see FIG. 1) is driven to advance the needle valve 29, thereby closing the injection flow path 31. Next, a fluid supply process (step S02) is performed. The plunger 11 is driven by the drive cylinder unit 13 to apply pressure to the test fluid.

[0022] Step S03 is carried out to check whether the test fluid leaks from the injection port 32. This check may be made visually by an engineer, or may be made automatically using a camera or the like. If there is no leakage of the test fluid from the injection port 32, it is determined that the sealing action of the needle valve 29 is normal (step S04). However, if leakage is detected, it is determined that there is a seal abnormality (step S05). The sealing action test is then completed.

[0023] <Leakage test from sliding points> The shut-off nozzle 2 is tested for leakage from sliding points in its valve structure. In the shut-off nozzle 2 being tested, the needle valve 29 slides relative to the needle hole 33. Therefore, the needle hole 33 is tested for leakage. As shown in FIG. 2B, an opening process (step S11) is performed. The needle valve drive piston cylinder unit 24 (see FIG. 1) is driven to move the needle valve 29 backward, opening the injection flow path 31. Next, a fluid supply process (step S12) is performed. The plunger 11 is driven by the drive cylinder unit 13 to inject the test fluid from the injection port 32. The limiter switch 15 stops driving the plunger 11 when it reaches its forward position.

[0024] Step S13 is carried out to check whether or not the test fluid is leaking from the needle hole 33. This check may be made visually by an engineer, or may be made automatically using a camera or the like. If there is no leakage of the test fluid from the needle hole 33, it is determined that the gap between the needle valve 29 and the needle hole 33 is within an appropriate range (step S14). On the other hand, if leakage is detected, it is determined that the gap between the needle valve 29 and the needle hole 33 has become large and is abnormal (step S15). The test for leakage from the sliding point is then completed.

[0025] <Second embodiment> The shut-off nozzle testing apparatus 1 according to this embodiment can be modified in various ways, and Fig. 3 shows a shut-off nozzle testing apparatus 1A according to a second embodiment. Members and parts similar to those of the testing apparatus 1 according to the first embodiment are given the same reference numerals and will not be described again.

[0026] <Resin supply device> The testing apparatus 1A according to the second embodiment is characterized in that it uses molten resin as the test fluid. To use molten resin, the testing apparatus 1A is equipped with a resin supplying device 35. The resin supplying device 35 includes a heating cylinder 36 and a melting plunger 38 that is slidably mounted within the heating cylinder 36. The heating cylinder 36 is provided with a hopper 39 and a heater 40 on its outer circumferential surface. Therefore, when the heating cylinder 36 is heated by the heater 40 and resin pellets as material are supplied from the hopper 39 and the melting plunger 38 is driven, the resin pellets are sent forward while melting.

[0027] <Methods for increasing fluid resistance> The resin supplying device 35 according to this embodiment is provided with a means for efficiently melting the resin, i.e., a flow path resistance increasing means. The flow path resistance increasing means increases the resistance of the flow path within the heating cylinder 36, and in this embodiment is made up of a flow path resistor 42. The flow path resistor 42, as shown in its side cross section in FIG. 4A, has a plurality of small-diameter through holes 43, 43, ... formed therein. Furthermore, as shown in its front cross section in FIG. 4B, the diameter of these through holes 43, 43, ... decreases in the downstream direction.

[0028] Therefore, when the resin pellets are melted and extruded by the melting plunger 38 (see FIG. 3), the cross-sectional area of ​​the bore of the heating cylinder 36, i.e., the cross-sectional area of ​​the flow path, decreases at the flow path resistor 42, and the resin pressure increases. This increase in pressure further increases the temperature of the molten resin. In addition, because the flow path resistor 42 is made of a metal with high thermal conductivity, the resin is heated more efficiently as it passes through the through-holes 43, 43, .... This allows the resin pellets to be melted efficiently.

[0029] A resin supply path 45 for supplying molten resin is opened in the support body 5 and the cylinder 7. The heating cylinder 36 of the resin supply device 35 is connected to the support body 5, and the bore of the heating cylinder 36 is connected to the resin supply path 45. Therefore, the resin molten in the resin supply device 35 is supplied into the cylinder 7. In the testing device 1A according to the second embodiment, a cylinder heater 47 is provided on the outer peripheral surface of the support body 5. This allows the test fluid, i.e., the molten resin, to be supplied into the cylinder 7 to be maintained at an appropriate temperature.

[0030] The testing apparatus 1A according to the second embodiment uses molten resin as the test fluid, and the testing method is the same as that of the first embodiment. Because molten resin is used, the shut-off nozzle 2 can be tested under conditions closer to practical use.

[0031] <Third embodiment> The testing apparatus 1A according to the second embodiment can be further modified. Specifically, the resin supply device 35 can be modified to form a third embodiment. FIG. 4C shows a resin supply device 35B provided in the third embodiment. The resin supply device 35B has a modified flow path resistance increasing means. In this embodiment, the flow path resistance increasing means is composed of a torpedo-shaped torpedo 49. The torpedo 49 can also effectively reduce the cross-sectional area of ​​the flow path, increasing the pressure of the resin and raising the temperature of the molten resin. Furthermore, the resin is efficiently heated and melted as it passes through the narrow flow path.

[0032] <Second type shut-off nozzle> The test apparatus 1 according to this embodiment can test various types of shut-off nozzles 2. FIG. 5 shows a second type of shut-off nozzle 2X attached to the test apparatus 1. The second type of shut-off nozzle 2X is composed of a nozzle body 50, a cylindrical rotary valve 51, and a rotary lever 52 that rotates the rotary valve 51. An injection flow path 54 is formed in the nozzle body 50, and its tip serves as an injection port 55. A cylindrical bore 56 is formed in the nozzle body 50 so as to cross the injection flow path 54. The rotary valve 51 is placed in the bore 56.

[0033] The rotary valve 51 has a through-hole 58 that penetrates it in the diameter direction. The rotary valve 51 is provided with a rotary lever 52. The rotary lever 52 is connected to a connecting bar 59, which is connected to the needle valve drive piston cylinder unit 24. Therefore, when the needle valve drive piston cylinder unit 24 is driven, the rotary valve can be rotated to the first or second rotation position. Because the needle valve drive piston cylinder unit 24 drives the rotary lever 52, it can also be called a rotary lever drive piston cylinder unit.

[0034] When the rotary valve 51 is rotated to the first rotation position, the injection passage 54 is aligned with the through-hole 58, opening the injection passage 54. On the other hand, when the rotary valve 51 is rotated to the second rotation position, the injection passage 54 is closed by the land portion of the rotary valve 51. In other words, the rotary valve 51 serves as a valve. In this second type shut-off nozzle 2X, a sliding portion is formed between the bore 56 and the rotary valve 51. Therefore, a leak test from the sliding portion detects whether or not the test fluid is leaking from the bore 56.

[0035] <Third type shut-off nozzle> 5 shows a third type shut-off nozzle 2Y attached to a testing device 1. The third type shut-off nozzle 2Y comprises a nozzle body 61, a needle valve 62, and an operating lever 63 for axially driving the needle valve 62. An injection flow path 64 is formed in the nozzle body 61, the tip of which forms an injection port 65. However, the injection flow path 64 branches and curves midway before merging and reaching the injection port 65. A support portion 67 is formed in this curved portion.

[0036] The needle valve 62 is inserted coaxially with the injection flow path 64, and its tip opens and closes the injection port 65. The rear end of the needle valve 62 is inserted into a support part 67. The end of the operating lever 63 is inserted into this support part 67 and connected to the rear end of the needle valve 62. The operating lever 63 is connected to the needle valve drive piston cylinder unit 24 via a connecting bar 69. Therefore, when the needle valve drive piston cylinder unit 24 is driven, the needle valve 62 is driven in the axial direction, and the injection port 65 is opened and closed. In this third type shut-off nozzle 2Y, the support part 67 is the sliding part. A leak test of the sliding part detects whether or not the test fluid is leaking from this part.

[0037] The invention made by the inventor has been specifically described above based on the embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments and various modifications are possible without departing from the spirit of the invention. The multiple examples described above can also be implemented in appropriate combinations. [Explanation of symbols]

[0038] 1 Test equipment 2 Shut-off nozzle 4 Housing 5 Support 6 Liquid reservoir 7 Cylinder 9 nozzle mounting member 11 plunger 13 Drive cylinder unit 14 Air supply source 15 Limiter switch 16 Piston 17 Fluid supply hole 18 Plug 20 Fluid supply pipe 21 Funnel 23 Bracket 24 Needle valve drive piston cylinder unit 25 Valve drive air supply source 26 Opening 28 Nozzle body 29 Needle valve 31 Injection channel 32 Injection outlet 33 needle hole 35 resin supply device 36 heating cylinder 38 melting plunger 39 Hopper 40 Heater 42 flow path resistor 43 through hole 45 Resin supply path 47 Cylinder heater 49 Torpedo 50 nozzle body 51 rotary valve 52 Rotating lever 54 Injection channel 55 Exit port 56 Bore 58 Through hole 59 Connecting bar 61 nozzle body 62 needle valve 63 Operating lever 64 Injection channel 65 Injection port 67 Support part 69 Connecting bar

Claims

1. A test device for a shut-off nozzle that is separate from the injection device of an injection molding machine, a cylinder containing a test fluid; a plunger disposed within the cylinder and adapted to pressurize the test fluid; a member for preventing the test fluid from scattering to the surroundings; a test shut-off nozzle having a nozzle body in which an injection flow path is formed and a valve structure for opening and closing the injection flow path is attached to the tip of the cylinder; The test fluid pressurized by the plunger is supplied to the shut-off nozzle; The member is adapted to cover a lower portion of the shut-off nozzle.

2. 2. The shut-off nozzle testing device according to claim 1, wherein the testing device comprises a driving cylinder unit that is operated by hydraulic pressure or air, and the plunger is driven by the driving cylinder unit.

3. 3. The shut-off nozzle testing device according to claim 1, wherein the testing device includes a limit switch for detecting the position of the plunger.

4. 4. The shut-off nozzle testing device according to claim 1, further comprising a valve driving means for driving the valve structure.

5. 5. The shut-off nozzle testing device according to claim 1, wherein the valve structure comprises a needle valve that opens and closes the injection flow path.

6. 6. A shut-off nozzle testing device as set forth in claim 5, wherein the nozzle body has a needle hole formed in its outer peripheral surface at an angle to the axial direction and reaching the injection flow path, and the needle valve is inserted into the needle hole so as to be able to move back and forth.

7. 6. The shut-off nozzle testing device according to claim 5, wherein the needle valve is provided coaxially in the injection flow path of the nozzle body, an operating lever is inserted into the nozzle body from its outer circumferential surface and connected to the rear end of the needle valve, and when the operating lever is driven to move the needle valve forward, the injection port at the tip of the nozzle body is closed, and when the operating lever is driven to move the needle valve backward, the injection port is opened.

8. 5. The shut-off nozzle testing device according to claim 1, wherein the valve structure comprises a cylindrical rotary valve having a through hole bored in a diameter direction, the rotary valve being rotatably inserted into a bore in the nozzle body that is bored across the injection passage, and rotated by a rotary lever, such that in a first rotation position the injection passage is aligned with the through hole to open the injection passage, and in a second rotation position the injection passage is closed by a land portion of the rotary valve.

9. the test fluid is a molten resin; The shut-off nozzle testing device according to any one of claims 1 to 8, wherein the testing device comprises a resin supplying device that melts resin and supplies the molten resin to the cylinder, and a cylinder heater that heats the cylinder.

10. The resin supply device has a resin flow path through which the resin flows while being molten, 10. The shut-off nozzle testing device according to claim 9, wherein a fluid resistance increasing means for reducing a cross-sectional area of ​​the resin flow path is provided in the resin flow path.

11. The shut-off nozzle to be tested is attached to the testing device according to any one of claims 1 to 10, a closing step of closing the injection flow path with the valve structure; a fluid supplying step of driving the plunger to supply the test fluid to the shut-off nozzle, thereby testing for leakage of the test fluid from the injection port at the tip of the nozzle body.

12. The shut-off nozzle to be tested is attached to the testing device according to any one of claims 1 to 10, an opening step of opening the injection flow path by the valve structure; a fluid supplying step of driving the plunger to supply the test fluid to the shut-off nozzle, and testing for the presence or absence of leakage of the test fluid from a sliding point formed between the nozzle body and the valve structure.

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