Method for manufacturing a fastening component and fastening component

Abstract

The present application relates to a method of manufacturing a fastening member and a fastening member. A method of manufacturing a fastening member (cylinder head (100)) fastened to a mounting object (cylinder barrel (10)) via a bolt (50) includes: a casting step of manufacturing the fastening member having a hole portion (56) by casting; and a through-hole forming step of forming a first through-hole (55a) through which the bolt (50) can be inserted by making the hole portion (56) through after the casting step.

Description

Technical Field

[0001] This invention relates to a method for manufacturing fastening components and to fastening components themselves. Background Technology

[0002] Japanese Patent Application Publication No. JPH3-249415A discloses a cylinder device comprising: a cylinder having an open end; a cylinder head installed to close the opening of the cylinder and secured by a plurality of bolts; a piston rod passing through the cylinder head and slidably disposed within the cylinder; and a piston mounted on the piston rod. Summary of the Invention

[0003] In the cylinder assembly described in Japanese Patent Application Publication No. JPH3-249415A, the number of bolts required to fix the cylinder head to the cylinder varies depending on specifications such as the pressure of the working fluid inside the cylinder. Furthermore, the cylinder head is generally formed using a mold and by casting. Therefore, multiple molds for manufacturing the cylinder head are required, corresponding to the number of bolts needed according to the specifications of the cylinder assembly, thus increasing the manufacturing cost of the cylinder head.

[0004] The purpose of this invention is to reduce the manufacturing cost of fastening components.

[0005] According to one aspect of the present invention, a method for manufacturing a fastening component that is fastened to an object by means of a bolt comprises: a casting step, which manufactures the fastening component having a hole by casting; and a through-hole forming step, which, after the casting step, passes through the hole to form a first through-hole through which the bolt can be inserted.

[0006] According to another aspect of the invention, a fastening member fastened to a mounting object by bolts comprises: a plurality of through holes arranged in a ring; and a hole portion arranged in a ring together with the plurality of through holes, wherein the fastening member is fastened to the mounting object by the bolts through the through holes. Attached Figure Description

[0007] Figure 1 This is a partial cross-sectional view of the fluid pressure cylinder according to an embodiment of the present invention. Figure 2 This is a top view of the cylinder head after the casting process. Figure 3 This is a top view of the cylinder head after the through-hole forming process. Figure 4 For along Figure 3 A cross-sectional view of the cylinder head along line IV-IV. Detailed Implementation

[0008] Referring to the accompanying drawings, a method for manufacturing a fastening component according to an embodiment of the present invention and the fastening component itself will be described. Hereinafter, the case where the fastening component is the cylinder head 100 of a hydraulic cylinder 1 driven by a working fluid will be described.

[0009] First, refer to Figure 1 The overall structure of hydraulic cylinder 1 will be described.

[0010] like Figure 1 As shown, the hydraulic cylinder 1 includes: a cylinder barrel 10; a piston rod 20, which is reciprocatingly disposed within the cylinder barrel 10; a piston 30, connected to the piston rod 20 and slidably housed within the cylinder barrel 10; and a cylinder head 100, which is fastened to the cylinder barrel 10 and closes the opening of the cylinder barrel 10. The piston rod 20 slidably inserts through the cylinder head 100, and the cylinder head 100 supports the piston rod 20. The cylinder head 100 is fastened to the end face 11 of the cylinder barrel 10, which is to be mounted, by a plurality of bolts 50.

[0011] The cylinder barrel 10 is formed in a cylindrical shape. The cylinder barrel 10 has a cylindrical body portion 12 and an annular connecting portion 13 on an end face 11 for fastening the cylinder head 100. A plurality of fastening holes 13a are formed on the connecting portion 13, each opening on the end face 11 for fastening with bolts 50. Female threads are formed in the fastening holes 13a. The other open end of the cylinder barrel 10 ( Figure 1 The piston rod 20 (not shown on the right) is blocked by the bottom of the cylinder (not shown). The cylinder 10 is divided into a rod-side chamber 2 and a rod-opposite-side chamber 3 by a piston 30. The rod-side chamber 2 and the rod-opposite-side chamber 3 are connected via a switching valve (not shown) to a hydraulic pump (not shown) or a fluid tank (not shown) as a hydraulic supply source. When one of the rod-side chamber 2 or the rod-opposite-side chamber 3 is connected to the hydraulic pump, the other is connected to the fluid tank. The hydraulic cylinder 1 is guided from the hydraulic pump to the rod-side chamber 2 or the rod-opposite-side chamber 3 by a working fluid, causing the piston rod 20 to move axially, thereby extending and retracting. Alternatively, a working fluid such as a water-soluble substitute fluid can be used instead of the working fluid. In other words, the fastening component can also be the cylinder head 100 of a hydraulic cylinder.

[0012] A supply and discharge port 45 is formed on the cylinder head 100, which connects to a hydraulic piping (not shown). An annular passage 46 is formed between the outer peripheral surface of the piston rod 20 and the inner peripheral surface of the through portion 42 of the cylinder head 100 (described later), connecting the supply and discharge port 45 and the rod-side chamber 2. Working fluid is supplied and discharged to the rod-side chamber 2 via the supply and discharge port 45 and the annular passage 46. The rod-side chamber 2 is divided by the cylinder barrel 10, the cylinder head 100, and the piston 30, and the opposite rod-side chamber 3 is divided by the cylinder barrel 10, the cylinder bottom, and the piston 30.

[0013] The piston rod 20 has: a small-diameter portion 21 formed at the top end and fastened to the piston 30; a large-diameter portion 22 that slides on the inner circumferential surface of the cylinder head 100 and is formed to be larger in diameter than the small-diameter portion 21; and a medium-diameter portion 23 formed between the small-diameter portion 21 and the large-diameter portion 22, for which an annular buffer ring 81, described later, is disposed. The outer diameter of the medium-diameter portion 23 is larger than that of the small-diameter portion 21 and smaller than that of the large-diameter portion 22. The buffer ring 81 is held between the piston 30 and the large-diameter portion 22.

[0014] The piston 30 is formed in an annular shape and is connected to the small-diameter portion 21 of the piston rod 20. A sealing member 31 is provided on the outer peripheral surface of the piston 30. This cuts off the communication between the rod-side chamber 2 and the opposite-side chamber 3 of the piston 30 via the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the piston 30.

[0015] When the hydraulic pump is connected to the rod-side chamber 2 and the fluid tank is connected to the opposite-side chamber 3, the working fluid is supplied to the rod-side chamber 2 via the supply and discharge port 45, and the working fluid in the opposite-side chamber 3 is discharged to the fluid tank. This causes the piston rod 20 to... Figure 1 As the piston moves to the right, hydraulic cylinder 1 retracts. Meanwhile, when the hydraulic pump is connected to the opposite chamber 3 and the fluid tank is connected to the rod-side chamber 2, working fluid is supplied to the opposite chamber 3, and the working fluid in the rod-side chamber 2 is discharged to the fluid tank via the supply / discharge port 45. This causes the piston rod 20 to move to the right. Figure 1 The hydraulic cylinder 1 extends as the cylinder moves to the left.

[0016] The buffer ring 81 is formed with a larger diameter than the large-diameter portion 22 of the piston rod 20, and is configured to enter the annular passage 46 between the outer circumferential surface of the large-diameter portion 22 of the piston rod 20 and the inner circumferential surface of the cylindrical portion 42 of the cylinder head 100. When the hydraulic cylinder 1 extends and the piston rod 20 is in its normal stroke range (not at the end of its stroke), the working fluid in the rod-side chamber 2 is guided to and discharged from the supply and discharge port 45 via the annular passage 46. On the other hand, when the hydraulic cylinder 1 extends and the piston rod 20 is near the end of its stroke, the buffer ring 81 enters the annular passage 46, and the working fluid in the rod-side chamber 2 is guided to and discharged from the supply and discharge port 45 via the buffer passage (not shown) formed between the outer circumferential surface of the buffer ring 81 and the inner circumferential surface of the cylindrical portion 42. Since the flow path cross-sectional area of ​​the buffer passage is smaller than that of the annular passage 46, the pressure in the rod-side chamber 2 increases, and the piston rod 20 decelerates. This creates a buffering effect.

[0017] Next, the cylinder head 100 will be described in detail.

[0018] The cylinder head 100 is made of metal and is formed primarily by casting. Figure 2 This is a top view of the unfinished cylinder head 100 after casting (specifically, after the casting process described later), as seen from the cylinder barrel 10 side. Figure 3 This is a top view of the cylinder head 100 as seen from the cylinder barrel 10 side, specifically after the through hole forming process described later. Figure 4 For along Figure 3 A sectional view of cylinder head 100 along line IV-IV. Figure 4 The right side of the cylinder is cylinder 10.

[0019] like Figure 1 , Figure 3 , Figure 4 As shown, the cylinder head 100 includes: a cylindrical portion 42; an annular flange portion 41 formed to extend radially from the cylindrical portion 42; and a plurality of through holes 55 (see reference). Figure 3 ) and multiple holes 56 (see reference) Figure 3 , Figure 4 ), which are formed on the same circumference on the flange portion 41. Additionally, in Figure 2 as well as Figure 3 In the top view shown, grid lines are drawn in the hole 56 to distinguish it from the through hole 55. However, as... Figure 4 As shown, hole 56 is a non-through hole, and its bottom is not grid-like. Additionally, in Figure 2 as well as Figure 3 In the top view shown, the supply and exhaust ports 45 are indicated by dashed lines.

[0020] A portion of the cylindrical section 42 fits into the inner circumferential surface of the cylinder 10 (see reference). Figure 1 A rod hole 44 is formed at the center of the cylindrical portion 42 for the piston rod 20 to pass through. The rod hole 44 supports the piston rod 20 (see reference). Figure 1 It also has a large diameter portion with a partially formed inner diameter. An annular passage 46 is formed between this large diameter portion and the outer peripheral surface of the piston rod 20.

[0021] The flange portion 41 is formed concentrically with the cylindrical portion 42 and is positioned to contact the annular end face 11 of the cylinder 10. For example... Figure 3As shown, on the flange portion 41, through holes 55 and hole portions 56 are formed at equal intervals in the circumferential direction on the same circumference centered on the axis of the rod hole 44. On the other hand, on the flange portion 41, through holes 55 and hole portions 56 are not formed in a portion A in the circumferential direction, but a supply and exhaust port 45 is formed in the radial direction in region A. Alternatively, the supply and exhaust port 45 may be formed in the cylinder barrel 10, and through holes 55 and hole portions 56 may be formed on the entire circumference of the flange portion 41. Furthermore, the through holes 55 and hole portions 56 do not need to be formed on the same circumference separately; they may be formed on the flange portion 41 offset from the same circumference. In other words, the cylinder head 100 only needs to have a plurality of through holes 55 arranged in a ring and hole portions 56 arranged in a ring together with the plurality of through holes 55.

[0022] Bolts 50 are inserted into multiple through holes 55. For example... Figure 2 , Figure 3 As shown, multiple through holes 55 are formed by the first through hole 55a (refer to...) Figure 3 The cylinder head 100 consists of a first through hole 55a formed by casting and a second through hole 55b formed by casting. The first through hole 55a is formed by passing through a portion of the plurality of holes 56 after casting. Thus, the first through hole 55a is provided as needed after casting and can be used for fastening the bolt 50. Details of the manufacturing method of the cylinder head 100 will be described later. The cylinder head 100 is fastened to the cylinder 10 by screwing the bolt 50 through the through holes 55 and the cylinder 10 fastening holes 13a into the cylinder 10, with the plurality of through holes 55 and the cylinder 10 fastening holes 13a respectively aligned. Preferably, the arrangement of the through holes 55 is symmetrical with respect to the axis of the rod hole 44. With this structure, the cylinder head 100 can be fastened to the cylinder 10 in a balanced and good manner. Since the holes 56 are open on the cylinder 10 side, the holes 56 that are not used as the first through hole 55a are closed by the end face 11 of the cylinder 10. Therefore, it is possible to prevent foreign objects from entering the hole 56. In addition, when the hydraulic cylinder 1 extends, the load borne by the cylinder head 100 acts on the cylindrical portion 42 and not on the flange portion 41 formed by the hole 56. Therefore, even with the hole 56, the strength of the cylinder head 100 is ensured.

[0023] Next, the manufacturing method of cylinder head 100 will be described in detail.

[0024] The method for manufacturing cylinder head 100 includes: a casting process, which manufactures cylinder head 100 having a plurality of holes 56 by casting; and a through hole forming process, which, after the casting process, makes at least one of the plurality of holes 56 pass through to form a first through hole 55a through which a bolt 50 can be inserted.

[0025] In the casting process, molten metal is poured into a mold corresponding to the shape of the cylinder head 100 and cooled, forming the flange portion 41 and the cylindrical portion 42 through casting. Additionally, in the casting process, such as... Figure 2 As shown, a second through hole 55b is formed together with multiple holes 56, through which bolts 50 can be inserted. Regarding the holes 56 and the second through hole 55b, the number of bolts 500 required to secure the cylinder head 100 to the cylinder barrel 10 varies depending on the specifications of the hydraulic cylinder 1, such as pressure. Specifically, when the hydraulic cylinder 1 is used at a higher pressure, or when the buffer pressure acting on the rod-side chamber 2 is used at a higher pressure, the cylinder head 100 needs to be secured more firmly relative to the cylinder barrel 10; therefore, the number of bolts 50 and the number of through holes 55 need to be increased. Therefore, in the casting process, the configuration and number of bolts 50 used to secure the cylinder head 100 when the hydraulic cylinder 1 is used under normal conditions are designed in advance, and the second through hole 55b is formed in the corresponding position. Furthermore, the configuration and number of additional bolts 50 when the hydraulic cylinder 1 is used at high pressure are designed in advance, and the holes 56 are formed in the corresponding positions. In other words, the mold used in the casting process is shaped as described above to form the second through hole 55b and the hole portion 56.

[0026] In the through-hole forming process, the first through-hole 55a is formed by penetrating the hole 56 in a manner that corresponds to the operating environment of the hydraulic cylinder 1 (specifications such as the pressure of the working fluid). Specifically, when the hydraulic cylinder 1 is used under high pressure, the number of bolts 50 is insufficient only because of the second through-hole 55b; therefore, the first through-hole 55a is formed by penetrating the hole 56 using a drill bit or the like. In this embodiment, the hole 56 is... Figure 2 Two of the four holes 56 shown are penetrated to form two first through holes 55a. This completes the cylinder head 100. Alternatively, the second through holes 55b formed in the casting process can be finished before or after the through hole forming process.

[0027] The plurality of fastening holes 13a of the cylinder 10 for bolt 50 fastening are formed according to the number and position of the first through holes 55a and the second through holes 55b formed as described above. Furthermore, it is preferable that the arrangement of the holes 56 formed in the casting process is opposite to region A in a manner that clamps the axis of the rod hole 44, or symmetrical with respect to the axis of the rod hole 44. Additionally, the arrangement of the second through holes 55b formed in the casting process and the arrangement of the first through holes 55a formed in the through hole forming process are preferably symmetrical with respect to the axis of the rod hole 44, respectively. In other words, in the finished cylinder head 100, it is preferable that the plurality of through holes 55 are formed in a point-symmetric manner with respect to the center (center of flange portion 41 and rod hole 44) of the same circumference where the plurality of through holes 55 and the hole portions 56 are formed. With this structure, the cylinder head 100 can be securely and evenly fastened to the cylinder 10.

[0028] Here, assuming that the cylinder head 100 does not have the hole 56 and the first through hole 55a, and the through hole 55 of the cylinder head 100 is formed only by casting, multiple molds for manufacturing the cylinder head 100 are required, corresponding to the number of bolts 50 (the number of through holes 55) that vary according to the specifications such as the pressure of the hydraulic cylinder 1. Therefore, this leads to an increase in the manufacturing cost of the cylinder head 100.

[0029] In contrast, in this embodiment, the cylinder head 100 with multiple holes 56 is manufactured by casting. Then, the holes 56 used for fastening the bolts 50 are passed through to form a first through hole 55a. Therefore, the number of through holes 56 can be determined solely based on the required number of bolts 50. This allows for the common use of molds for manufacturing the cylinder head 100 regardless of the required number of bolts 50. Consequently, the manufacturing cost of the cylinder head 100 can be reduced.

[0030] In addition, in this embodiment, the second through hole 55b that can be inserted by the bolt 50 is pre-formed by casting, so the number of working hours for forming the first through hole 55a in the through hole forming process can be reduced.

[0031] Alternatively, during the casting process, the second through hole 55b may not be formed, and only multiple holes 56 may be formed. In other words, the through hole 55 may simply be the first through hole 55a formed during the through hole forming process. Even with this structure, only one mold for manufacturing the cylinder head 100 can be used, regardless of the number of bolts 50 required.

[0032] Alternatively, during the casting process, only one hole 56 can be formed, and during the through-hole forming process, the hole 56 can be made to pass through to form a first through-hole 55a through which a bolt 50 can be inserted. Even with this structure, the molds for manufacturing the cylinder head 100 can be common in a way that does not depend on the number of bolts 50 required, thereby reducing the manufacturing cost of the cylinder head 100.

[0033] According to the above implementation method, the following effects are achieved.

[0034] In the cylinder head 100 manufacturing method of this embodiment, a cylinder head 100 having a plurality of holes 56 is manufactured by casting. Then, a first through hole 55a is formed by passing through one of the plurality of holes 56 used for fastening the bolts 50. Therefore, the number of through holes 56 can be determined only according to the required number of bolts 50. As a result, the mold for manufacturing the cylinder head 100 can be common in a manner that is independent of the required number of bolts 50. Therefore, the manufacturing cost of the cylinder head 100 can be reduced.

[0035] In the cylinder head 100 of this embodiment, even if the required number of bolts 50 is increased, the through hole 56 can be made to serve as a through hole 55 for fastening the bolts 50. Therefore, even when the cylinder head 100 is manufactured by casting, the mold for manufacturing the cylinder head 100 can be standardized regardless of the required number of bolts 50. Thus, the manufacturing cost of the cylinder head 100 can be reduced.

[0036] Next, variations of this embodiment will be described. The following variations are also within the scope of the present invention, and the following variations can be combined with the structures of the above-described embodiments or combined with each other.

[0037] <Modification 1> In the above embodiment, during the through-hole forming process, there are non-through hole portions 56. However, this is not a limitation; all hole portions 56 can be formed through the hole during the through-hole forming process to create the first through-hole 55a, or, as described above, only one hole portion 56 can be formed through the hole during the through-hole forming process to create the first through-hole 55a through which a bolt 50 can be inserted. That is, in the cylinder head 100 manufacturing method, during the through-hole forming process, it is sufficient to form the first through-hole 55a through which a bolt 50 can be inserted, as long as the hole portions 56 are formed through the hole.

[0038] <Modification 2> In the above embodiment, the fastening component is the cylinder head 100 of the hydraulic cylinder 1. However, the fastening component is not limited to the cylinder head 100; it can be fastened to the mounting object via bolts 50. For example, the fastening component may also be a component that connects the end of the eye-type bracket used to mount the hydraulic cylinder 1 to the device or the like to the end of the piston rod 20. In this structure, the fastening component that is threaded to the end of the piston rod 20 has multiple through holes 55 and holes 56, and is fastened to the eye-type bracket, which is the mounting object, via bolts 50. Alternatively, the fastening component may be integrally formed with the piston rod 20. Alternatively, the fastening component may be integrally formed with the eye-type bracket and fastened to the piston rod 20, which is the mounting object, via bolts 50.

[0039] The structure, function, and effects of the embodiments of the present invention as described above are summarized and explained.

[0040] The manufacturing method of the fastening component (cylinder head 100) that is fastened to the mounting object (cylinder barrel 10) by bolt 50 includes: a casting process, which manufactures the fastening component having a hole 56 by casting; and a through hole forming process, which, after the casting process, makes the hole 56 pass through to form a first through hole 55a through which the bolt 50 can be inserted.

[0041] In this structure, a fastening component with holes 56 is manufactured by casting. Then, the holes 56 used for fastening the bolts 50 are passed through to form a first through hole 55a. Therefore, the number of through holes 56 can be determined solely by the number of bolts 50 required. This allows for the standardization of molds for manufacturing the fastening component, regardless of the required number of bolts 50. Consequently, the manufacturing cost of the fastening component can be reduced.

[0042] In addition, in the manufacturing method of the fastening component, during the casting process, a second through hole 55b is formed on the fastening component, through which a bolt 50 can be inserted.

[0043] In this structure, a second through hole 55b that allows the bolt 50 to be inserted is pre-formed by casting, thus reducing the number of working hours required to form the first through hole 55a in the through hole forming process.

[0044] In addition, in the manufacturing method of the fastening component, the fastening component having multiple holes 56 is manufactured by casting in the casting process.

[0045] In this structure, the number of through holes 56 can be determined solely by the number of bolts 50 required, allowing for the standardization of molds for manufacturing fasteners in a manner independent of the required number of bolts 50. Therefore, the manufacturing cost of fasteners can be reduced.

[0046] In addition, the fastening component (cylinder head 100) which is fastened to the mounting object (cylinder barrel 10) by bolt 50 has a plurality of through holes 55 arranged in a ring and a hole portion 56 arranged in a ring together with the plurality of through holes 55. The fastening component is fastened to the mounting object by bolt 50 through the through holes 55.

[0047] In this structure, even if the required number of bolts 50 is increased, the through hole 56 can be made to serve as the through hole 55 used for fastening the bolts 50. Therefore, even when the fastening component is manufactured by casting, the mold for manufacturing the fastening component can be standardized in a way that does not depend on the required number of bolts 50. Thus, the manufacturing cost of the fastening component can be reduced.

[0048] In addition, the fastening component also has an annular flange portion 41 with a plurality of through holes 55 and holes 56, and the plurality of through holes 55 are formed in a point-symmetric manner with respect to the center of the flange portion 41.

[0049] This structure allows for the balanced and secure fastening of fastening components to the mounting object.

[0050] Additionally, the fastening component is the cylinder head 100 of the hydraulic cylinder (hydraulic cylinder 1).

[0051] This structure can reduce the manufacturing cost of the cylinder head 100.

[0052] In addition, the fastening component (cylinder head 100) is blocked by the cylinder 10 of the hydraulic pressure cylinder, which is the object to be installed.

[0053] This structure prevents foreign objects from entering the hole 56.

[0054] The embodiments of the present invention have been described above. However, the above embodiments are merely some examples of the application of the present invention and are not intended to limit the technical scope of the present invention to the specific structures of the above embodiments.

Claims

1. A method for manufacturing a fastening component, wherein the fastening component is fastened to an object being mounted by bolts, wherein, The method for manufacturing the fastening component includes: The casting process manufactures the fastening component having holes by casting; The through-hole forming process involves passing the hole through after the casting process, thereby forming a first through-hole through which the bolt can be inserted.

2. The method for manufacturing the fastening component as described in claim 1, wherein, In the casting process, a second through hole is formed on the fastening component, through which the bolt can be inserted.

3. The method for manufacturing the fastening component as described in claim 1, wherein, In the casting process, the fastening component having a plurality of the aforementioned holes is manufactured by casting.

4. A fastening component, fastened to an object by bolts, wherein, have: Multiple through holes are arranged in a ring. The perforation, together with the plurality of through holes, is formed in a ring arrangement. The fastening component is fastened to the mounting object by means of the bolt through the through hole.

5. The fastening component as claimed in claim 4, wherein, It also includes an annular flange portion having the plurality of through holes and the hole portions. The plurality of through holes are formed in a point-symmetric manner with respect to the center of the flange.

6. The fastening component as claimed in claim 4, wherein, The fastening component is the cylinder head of the hydraulic pressure cylinder.

7. The fastening component as claimed in claim 6, wherein, The orifice is blocked by the cylinder of the liquid pressure cylinder, which is the object to be installed.

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