Shut-off nozzle, injection device, and injection molding machine

Abstract

To provide a shut-off nozzle capable of preventing drooling.SOLUTION: There is provided a shut-off nozzle (24) composed of a nozzle body portion (28) having an in-nozzle flow path (27) formed therein, and a needle valve (30) inserted into the nozzle body portion (28) coaxially with the nozzle body portion (28) and configured to open and close an outlet of the in-nozzle flow path (27). A cylindrical portion (46) is formed in the vicinity of a tip portion of the needle valve (30). A cylindrical hole portion (45) being a cylindrical hole is formed in the vicinity of a tip portion of the in-nozzle flow path (27). The cylindrical portion (46) is configured to be fitted into the cylindrical hole portion (45) when the needle valve (30) is made to proceed forward.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to a shut-off nozzle in which a needle valve is coaxially provided on a nozzle body to open and close a resin flow path, an injection apparatus provided with such a shut-off nozzle, and an injection molding machine.

Background Art

[0002] A shut-off nozzle provided in an injection apparatus of an injection molding machine opens and closes an injection flow path through which a resin of the injection nozzle flows, and is capable of preventing so-called drooling. Shut-off nozzles include, for example, a type as described in Patent Document 1. This type of shut-off nozzle consists of a nozzle body and a needle valve provided obliquely with respect to the nozzle body. The needle valve is inserted into an oblique needle hole bored from the outer circumferential surface of the nozzle body to reach the inner injection flow path. When the needle valve is advanced, the injection flow path is closed, and when the needle valve is retracted, the injection flow path is opened.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] Some shut-off nozzles have a needle valve that is mounted coaxially with the nozzle body. In this type of shut-off nozzle, the needle valve is inserted into the injection channel formed in the nozzle body and is able to move back and forth. The tip of the needle valve is tapered, with a reduced diameter. When the needle valve moves forward, its tip is inserted into the tip of the injection channel formed in the nozzle body. The tapered surface then comes into contact with the inner surface of the injection channel, closing the injection channel. However, even when the injection channel is closed by the needle valve, the closure of the injection channel by contact between the tapered surface and the inner surface of the injection channel is not always sufficient, which can lead to resin leakage and drooling.

[0005] This disclosure provides a shut-off nozzle that can prevent drooling.

[0006] Other challenges and novel features will become apparent from the description and accompanying drawings in this specification. [Means for solving the problem]

[0007] This disclosure relates to a shut-off nozzle comprising a nozzle body portion having an internal flow path formed therein, and a needle valve inserted coaxially with the nozzle body portion to open and close the outlet of the internal flow path. A cylindrical portion is formed near the tip of the needle valve, and the tip is formed into a flat end face. A cylindrical hole portion, which is a cylindrical hole, is formed near the tip of the internal flow path of the nozzle, and the tip of the cylindrical hole portion In this, the cylindrical hole portion is formed to have a smaller diameter. Stepped section It forms. This disclosure provides a configuration in which, when the needle valve is driven in the forward direction, the cylindrical portion fits into the cylindrical hole and the end face abuts against the stepped portion. [Effects of the Invention]

[0008] This disclosure can prevent drowning. [Brief explanation of the drawing]

[0009] [Figure 1]This is a front view showing an injection molding machine according to the first embodiment. [Figure 2] This is a front cross-sectional view showing a shut-off nozzle according to the first embodiment. [Figure 3A] This is a front cross-sectional view showing an enlarged portion of the shut-off nozzle according to the first embodiment. [Figure 3B] This is a front cross-sectional view showing an enlarged portion of the shut-off nozzle according to the first embodiment. [Figure 4] This is a front cross-sectional view showing an enlarged portion of the shut-off nozzle according to the first embodiment. [Figure 5A] This is a front cross-sectional view showing a magnified portion of the shut-off nozzle relating to the comparative example. [Figure 5B] This is a front cross-sectional view showing a magnified portion of the shut-off nozzle relating to the comparative example. [Figure 6] This is a front cross-sectional view showing an enlarged portion of a shut-off nozzle according to a modified example of the first embodiment. [Figure 7A] This is a front cross-sectional view showing an enlarged portion of the shut-off nozzle according to the second embodiment. [Figure 7B] This is a front cross-sectional view showing an enlarged portion of the shut-off nozzle according to the second embodiment. [Figure 8] This is a front cross-sectional view showing a shut-off nozzle according to a modified example of the first and second embodiments. [Modes for carrying out the invention]

[0010] The following describes specific embodiments in detail with reference to the drawings. However, the embodiments are not limited to those described below. For clarity, the following descriptions and drawings have been simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanations have been omitted where necessary. Also, hatching has been omitted in some parts of the drawings to avoid clutter.

[0011] [First Embodiment] <Injection molding machine> An injection molding machine 1 according to a first embodiment includes a mold clamping device 2 and an injection device 3, as illustrated in FIG. 1. The injection molding machine 1 includes a controller, that is, a control device 4, and the mold clamping device 2, the injection device 3, and the like are configured to be controlled by the control device 4. As will be described in detail later, the injection device 3 is provided with a shut-off nozzle 24 having a characteristic structure.

[0012] <Mold Clamping Device> The mold clamping device 2 includes a stationary platen 7 fixed to a bed B, a movable platen 8 provided slidably on the bed B, and a mold clamping housing 9. The stationary platen 7 and the mold clamping housing 9 are connected by a plurality of tie bars 11, 11, ..., and the movable platen 8 is slidable between the stationary platen 7 and the mold clamping housing 9. A mold clamping mechanism, that is, a toggle mechanism 13 in the present embodiment, is provided between the mold clamping housing 9 and the movable platen 8. A stationary mold 15 and a movable mold 16 are provided on the stationary platen 7 and the movable platen 8, respectively. Accordingly, when the toggle mechanism 13 is driven, the molds 15 and 16 are opened and closed.

[0013] <Injection Device> The injection device 3 includes a heating cylinder 19, a screw 20 provided in the heating cylinder 19, and a screw driving device 22. The heating cylinder 19 is supported by the screw driving device 22, and the screw 20 is configured to be driven in a rotational direction and an axial direction by the screw driving device 22. The heating cylinder 19 is provided with a hopper 23 and the shut-off nozzle 24 according to the first embodiment which will be described in detail below.

[0014] <Shut-off Nozzle> A shut-off nozzle 24 according to the first embodiment is shown in FIG. 2. The shut-off nozzle 24 includes: a nozzle main body 28 having in-nozzle flow paths 26 and 27 formed therein; a needle valve 30 housed in the nozzle main body 28; and a needle drive mechanism 32 that drives the needle valve 30. When viewed with reference to the central axis of a horizontally arranged heating cylinder 19, the nozzle main body 28 is arranged substantially coaxially with the heating cylinder 19. The needle valve 30 is arranged coaxially with respect to the nozzle main body 28 and is housed in the in-nozzle flow path 27.

[0015] Communication holes 34, 34 that communicate the in-nozzle flow paths 26 and 27 are opened in the nozzle main body 28. Accordingly, resin fed from the heating cylinder 19 passes through the in-nozzle flow path 26, the communication holes 34, 34, and the in-nozzle flow path 27, and is then injected from an outlet, that is, an injection port 35. A needle hole 36 is opened in an internal member of the nozzle main body 28, and a rear end portion of the needle valve 30 is fitted into the needle hole 36 so that the needle valve 30 can move forward and backward freely.

[0016] The needle drive mechanism 32 includes: an annular cylinder mechanism 38 provided so as to surround an outer periphery of the nozzle main body 28; and a spring receiver 39 driven by the cylinder mechanism 38. The spring receiver 39 is housed in a spring receiver accommodation hole 41 that penetrates the nozzle main body 28 in a direction perpendicular to the axis, and is slidable back and forth within the spring receiver accommodation hole 41. A rear end portion of the needle valve 30 is connected to such a spring receiver 39. Accordingly, when compressed air is supplied from an air supply pipe 43, the cylinder mechanism 38 is driven, and the needle valve 30 moves forward or backward via the spring receiver 39. Thereby, the in-nozzle flow path 27 is opened and closed.

[0017] The shut-off nozzle 24 according to the first embodiment is characterized by its shape near the tip of the nozzle body 28. Specifically, it is the shape of the tip of the nozzle internal flow path 27. As shown in an enlarged view in Figure 3A, a cylindrical hole 45 is formed in the nozzle internal flow path 27 over a length L. The inner diameter of the cylindrical hole 45 is slightly larger than the outer diameter of the needle valve 30 in the first embodiment. As will be explained later, a portion of the same length near the tip of the needle valve 30, i.e., a cylindrical portion 46, is fitted into this cylindrical hole 45. The cylindrical hole 45 can be machined, for example, using an end mill capable of drilling. By forming the cylindrical hole 45 with an end mill, it is possible to machine it to the desired inner diameter with high accuracy without finishing. In other words, it can be machined at low cost while obtaining the required accuracy.

[0018] The shut-off nozzle 24 according to the first embodiment also features a needle valve 30. In the needle valve 30, the portion from the cylindrical part 46 to the tip is a guide part 47 that tapers towards the tip. Because of this tapering, the needle valve 30 can be smoothly inserted into the cylindrical hole 45.

[0019] <The function of the shut-off nozzle> The operation of the shut-off nozzle 24 according to the first embodiment will now be described. Compressed air is supplied to the cylinder mechanism 38 of the needle drive mechanism 32 (see Figure 2), causing the needle valve 30 to retract via the spring receiver 39. As a result, as shown in Figure 3A, the needle valve 30 moves away from the cylindrical hole 45, and the nozzle internal passage 27 is opened. The screw 20 in the injection device 3 (see Figure 1) is driven in the forward direction. As a result, the resin is sent forward and injected from the nozzle port 35 through the nozzle internal passage 27 (see Figure 3A) of the shut-off nozzle 24.

[0020] Once injection is complete, compressed air is supplied to the cylinder mechanism 38 of the needle drive mechanism 32 (see Figure 2), and the needle valve 30 is advanced via the spring retainer 39. As a result, the cylindrical portion 46 of the needle valve 30 fits into the cylindrical hole portion 45 of the nozzle body portion 28, as shown in Figure 3B. This is shown in an enlarged view in Figure 4. As mentioned above, the inner diameter of the cylindrical hole portion 45 is slightly larger than the outer diameter of the cylindrical portion 46 of the needle valve 30. In other words, the fitting is a clearance fit, and a mechanical seal portion 49 is formed.

[0021] The mechanical seal portion 49 is an annular gap with length L into which the resin enters. However, because the gap is small, high flow resistance is generated due to the viscosity of the resin. Flow resistance occurs for the length of the mechanical seal portion 49, that is, for the length L of the cylindrical hole portion 45. Since it consists of a thin cylinder over length L, the mechanical seal portion 49 has a relatively large surface area. Therefore, the resin cannot flow due to the flow resistance. In other words, the flow path 27 inside the nozzle is substantially completely closed. Drooling is prevented.

[0022] Furthermore, after prolonged operation, the inner diameter of the cylindrical hole 45 expands slightly, or the outer diameter of the cylindrical part 46 decreases slightly, resulting in a slightly larger gap. However, the resin flow resistance acting on the entire mechanical seal part 49 remains sufficiently large. Therefore, drooling is prevented over the long term. Similarly, even if the inner diameter of the cylindrical hole 45 is slightly larger, or the outer diameter of the cylindrical part 46 is slightly smaller due to machining accuracy, the resin flow resistance acting on the entire mechanical seal part 49 remains sufficiently large. This is because the mechanical seal part 49, which consists of a thin cylinder, is subjected to flow resistance over its length L. In other words, drooling is prevented. The required machining accuracy is relatively lenient.

[0023] <Comparative Example> Figures 5A and 5B illustrate the comparative example of the shut-off nozzle 101. The comparative example of the shut-off nozzle 101 can also be attached to the injection molding machine 1 shown in Figure 1, and is driven by the needle drive mechanism 32 shown in Figure 2. Therefore, a detailed explanation of these is omitted. Figures 5A and 5B show the vicinity of the tip of the nozzle body 102 and the vicinity of the tip of the needle valve 103 of the comparative example of the shut-off nozzle 101. The nozzle body 102 has an internal nozzle passage 105, and the needle valve 103 is placed coaxially with the nozzle body 102 in this internal nozzle passage 105. The tip of the needle valve 103 is formed in a conical shape. The internal nozzle passage 105 is formed as a conical surface 106 near the tip of the nozzle body 102.

[0024] When the needle valve 103 moves forward, its tip sits on the conical surface 106, closing the nozzle's internal passage 105. However, perfectly matching the shapes of the conical surface 106 and the tip of the needle valve 103 is difficult due to manufacturing precision limitations. Therefore, the tip of the needle valve 103 does not make surface contact with the conical surface 106, but rather makes linear contact as indicated by reference numeral 108 in Figure 5A. Alternatively, depending on the shape of the conical surface 106, it may make linear contact as indicated by reference numeral 109 in Figure 5B. Even if only a linear portion is in contact, the nozzle's internal passage 105 will be closed. However, after prolonged operation, the conical surface 106 may deform due to wear, or the tip of the needle valve 103 may chip, causing the seal to break. This then results in drooling.

[0025] The comparative example, the shut-off nozzle 101, has a problem in that drooling is prone to occur when the resin pressure increases in the nozzle's internal flow path 105. As indicated by reference numeral 110 in Figure 5A and reference numeral 111 in Figure 5B, when the needle valve 30 closes the nozzle's internal flow path 105, a portion of the conical tip of the needle valve 30 is exposed in the nozzle's internal flow path 105. The resin pressure in the nozzle's internal flow path 105 acts on the portions indicated by reference numerals 110 and 111, causing a retractive force to act on the needle valve 103. This makes drooling more likely to occur.

[0026] In contrast, the shut-off nozzle 24 according to the first embodiment, as shown in Figure 4, has no conical structure exposed in the nozzle's internal flow path 27 when the cylindrical portion 46 of the needle valve 30 is fitted into the cylindrical hole 45. Therefore, even if the resin pressure in the nozzle's internal flow path 27 increases, no force acts on the needle valve 30 in the backward direction. In other words, drooling does not occur even if the resin pressure in the nozzle's internal flow path 27 increases.

[0027] However, the shut-off nozzle 101 in the comparative example has the problem that the machining of the conical surface 106 in the nozzle body 102 is costly. This is because, in order to form such a conical surface 106, it is necessary to finish the machining with a tapered reamer, which has a tapered tip, after drilling the hole with an end mill, for example. The tapered reamer also needs to be custom-made to match the apex angle of the cone of the conical surface 106. In contrast, in the shut-off nozzle 24 according to the first embodiment, the cylindrical hole 45 in the nozzle body 28 can be machined using an end mill as described above. Therefore, the cost required for machining is small.

[0028] <Modified form of the first embodiment> The shut-off nozzle 24 according to the first embodiment (see Figures 3A, 3B, and 4) can be modified in various ways. For example, the guide portion 47 at the tip of the needle valve 30 (see Figure 4) can be eliminated. Figure 6 shows a modified shut-off nozzle 24' in which the tip of the needle valve 30' is deformed into a flat end face 51. In this shut-off nozzle 24', the vicinity of the tip of the nozzle internal flow path 27 in the nozzle body portion 28' is also deformed, and the tip of the cylindrical hole portion 45 is formed into a stepped portion 52. The modified shut-off nozzle 24' is also provided in the injection molding machine 1 shown in Figure 1, and is configured as shown in Figure 2, except for the shape of the tip of the needle valve 30' and the shape of the tip of the nozzle body portion 28'. Therefore, a detailed explanation of these is omitted.

[0029] <Second Embodiment> The second embodiment will be explained with reference to Figures 7A and 7B. The configuration of the injection molding machine according to the second embodiment is basically the same as the configuration of the injection molding machine 1 according to the first embodiment (see Figure 1). The configuration of the shut-off nozzle 24A is also basically the same as the configuration of the shut-off nozzle 24 according to the first embodiment shown in Figure 2. The only difference from the first embodiment is a part of the shut-off nozzle 24A, namely the configuration of the needle valve 30A and the nozzle body 28A. Therefore, a description of the configuration of the injection molding machine and the overall configuration of the shut-off nozzle 24A will be omitted.

[0030] As shown in Figure 7A, in the shut-off nozzle 24A according to the second embodiment, a plurality of cylindrical holes 53 and 54 are formed at the tip of the nozzle body 28A. These are the first cylindrical hole 53 and the second cylindrical hole 54. The second cylindrical hole 54 is formed closer to the tip than the first cylindrical hole 53 and has a smaller diameter. Their respective lengths are L1 and L2.

[0031] Corresponding to these first and second cylindrical bore portions 53 and 54, the needle valve 30A is equipped with a first cylindrical portion 56 and a second cylindrical portion 57 at its tip. The inner diameter of the first cylindrical bore portion 53 is slightly larger than the outer diameter of the first cylindrical portion 56, and the inner diameter of the second cylindrical bore portion 54 is slightly larger than the outer diameter of the second cylindrical portion 57. When the needle valve 30A is advanced, as shown in Figure 7B, the first cylindrical portion 56 fits into the first cylindrical bore portion 53, and the second cylindrical portion 57 fits into the second cylindrical bore portion 54, forming the first and second mechanical seal portions 58 and 59. The first and second mechanical seal portions 58 and 59 obstruct the flow of resin and prevent drooling.

[0032] <Other variations> The injection molding machine 1 according to the first embodiment can be modified in other ways. For example, in the shut-off nozzle 24 (see Figure 2), the needle drive mechanism 32 that drives the needle valve 30 can be modified. Figure 8 shows a shut-off nozzle 24B equipped with a modified needle drive mechanism 32B. In this shut-off nozzle 24B, a lever 60 is placed in the nozzle body 28B, and the lever 60 is connected to the needle valve 30 and is designed to pivot around a rotation axis 61. The lever 60 is connected to an air-driven cylinder unit 62. Therefore, when compressed air is supplied to the cylinder unit 62, the lever 60 pivots, causing the needle valve 30 to move forward or backward. This opens and closes the flow path 27 inside the nozzle.

[0033] Other modifications are also possible. In the second embodiment, the shut-off nozzle 24A (see Figure 7A) was described as having two cylindrical holes 53 and 54 formed in the nozzle body 28A. However, the number of cylindrical holes 53, 54, ... may be three or more. In this case, the number of cylindrical parts 56, 57, ... provided in the needle valve 30A must also be the same.

[0034] The present invention has been described in detail above based on embodiments, but it goes without saying that the present invention is not limited to the embodiments already described, and various modifications are possible without departing from the spirit of the invention. The multiple examples described above can also be implemented in combination as appropriate. [Explanation of Symbols]

[0035] 1 Injection molding machine 2 Mold clamping device 3. Injection device 4. Control device 7 Fixed plate 8 Movable plate 9-type clamping housing 11 tie bars 13 Toggle mechanism 15 Fixed side mold 16 Movable mold 19 Heating cylinder 20 Screw 22 Screw drive mechanism 23 Hopper 24 Shut-off nozzle 26 Nozzle internal flow path 27 Nozzle internal flow path 28 Nozzle body 30 Needle valve 32 Needle drive mechanism 34 Communication hole 35 Outlet 36 Needle hole 38 Cylinder mechanism 39 Spring receiver 41 Spring retainer storage hole 43 Air supply pipe 45 Cylindrical hole section 46 Cylindrical section 47 Guide section 49 Mechanical seal section 51 End face 52 Stepped part 53 First cylindrical hole 54 Second cylindrical hole 56 First cylindrical section 57 Second cylindrical section 58 First mechanical seal section 59 Second mechanical seal section

Claims

1. A nozzle body portion having an internal flow path formed inside, The nozzle body is provided with a needle valve that is inserted coaxially with the nozzle body and opens and closes the outlet of the internal flow path of the nozzle, A cylindrical portion is formed near the tip of the needle valve, and the tip is formed into a flat end face. A cylindrical hole is formed near the tip of the internal flow path of the nozzle, and a stepped portion is formed at the tip of the cylindrical hole by making it smaller in diameter than the cylindrical hole. A shut-off nozzle in which, when the needle valve is driven in the forward direction, the cylindrical portion fits into the cylindrical hole and the end face abuts against the stepped portion.

2. A nozzle body portion having a nozzle internal flow path formed inside, The nozzle body is provided with a needle valve that is inserted coaxially with the nozzle body and opens and closes the outlet of the internal flow path of the nozzle, Near the tip of the needle valve, a first cylindrical portion and a second cylindrical portion on the tip side are formed, and the second cylindrical portion has a smaller diameter than the first cylindrical portion. Near the tip of the nozzle's internal flow path, a first cylindrical hole and a second cylindrical hole on the tip side are formed, and the second cylindrical hole has a smaller diameter than the first cylindrical hole. A shut-off nozzle in which, when the needle valve is advanced, the first cylindrical portion fits into the first cylindrical hole and the second cylindrical portion fits into the second cylindrical hole, and the stepped portion at the boundary between the first and second cylindrical portions abuts against the stepped portion at the boundary between the first and second cylindrical holes.

3. A heating cylinder and The screw placed in the heating cylinder, The heating cylinder is provided with a shut-off nozzle, The aforementioned shut-off nozzle comprises a nozzle body portion in which an internal flow path is formed, The nozzle body is provided with a needle valve that is inserted coaxially with the nozzle body and opens and closes the outlet of the internal flow path of the nozzle, A cylindrical portion is formed near the tip of the needle valve, and the tip is formed into a flat end face. A cylindrical hole is formed near the tip of the internal flow path of the nozzle, and a stepped portion is formed at the tip of the cylindrical hole by making it smaller in diameter than the cylindrical hole. An injection device in which, when the needle valve is driven in the forward direction, the cylindrical portion fits into the cylindrical hole and the end face abuts against the stepped portion.

4. A heating cylinder and The screw placed in the heating cylinder, The heating cylinder is provided with a shut-off nozzle, The aforementioned shut-off nozzle comprises a nozzle body portion in which an internal flow path is formed, The nozzle body is provided with a needle valve that is inserted coaxially with the nozzle body and opens and closes the outlet of the internal flow path of the nozzle, Near the tip of the needle valve, a first cylindrical portion and a second cylindrical portion on the tip side are formed, and the second cylindrical portion has a smaller diameter than the first cylindrical portion. Near the tip of the nozzle's internal flow path, a first cylindrical hole and a second cylindrical hole on the tip side are formed, and the second cylindrical hole has a smaller diameter than the first cylindrical hole. An injection device in which, when the needle valve is advanced, the first cylindrical portion fits into the first cylindrical hole, and the second cylindrical portion fits into the second cylindrical hole, and the stepped portion at the boundary between the first cylindrical portion and the second cylindrical portion abuts against the stepped portion at the boundary between the first cylindrical hole and the second cylindrical hole.

5. An injection device for injecting resin, It includes a mold clamping device for clamping the mold, The injection device includes a heating cylinder, The screw placed in the heating cylinder, The heating cylinder is provided with a shut-off nozzle, The aforementioned shut-off nozzle comprises a nozzle body portion in which an internal flow path is formed, The nozzle body is provided with a needle valve that is inserted coaxially with the nozzle body and opens and closes the outlet of the internal flow path of the nozzle, A cylindrical portion is formed near the tip of the needle valve, and the tip is formed into a flat end face. A cylindrical hole is formed near the tip of the internal flow path of the nozzle, and a stepped portion is formed at the tip of the cylindrical hole by making it smaller in diameter than the cylindrical hole. An injection molding machine in which, when the needle valve is driven in the forward direction, the cylindrical portion fits into the cylindrical hole and the end face abuts against the stepped portion.

6. An injection device for injecting resin, It includes a mold clamping device for clamping the mold, The injection device includes a heating cylinder, The screw placed in the heating cylinder, The heating cylinder is provided with a shut-off nozzle, The aforementioned shut-off nozzle comprises a nozzle body portion in which an internal flow path is formed, The nozzle body is provided with a needle valve that is inserted coaxially with the nozzle body and opens and closes the outlet of the internal flow path of the nozzle, Near the tip of the needle valve, a first cylindrical portion and a second cylindrical portion on the tip side are formed, and the second cylindrical portion has a smaller diameter than the first cylindrical portion. Near the tip of the nozzle's internal flow path, a first cylindrical hole and a second cylindrical hole on the tip side are formed, and the second cylindrical hole has a smaller diameter than the first cylindrical hole. An injection molding machine in which, when the needle valve is advanced, the first cylindrical portion fits into the first cylindrical hole, and the second cylindrical portion fits into the second cylindrical hole, and the stepped portion at the boundary between the first cylindrical portion and the second cylindrical portion abuts against the stepped portion at the boundary between the first cylindrical hole and the second cylindrical hole.

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