Pressure-resistant device and fluid pressure cylinder

Abstract

A pressure-resistant device (100, 200, 300, 400, 500, 600) comprising: a tubular main body section (110, 510) which has an opening end section (110a, 510a); a lid section (120, 520, 620) having an annular wall section (122, 522, 622) with a leading end section (122a, 522a, 622a), the wall section (122, 522, 622) and the main body section (110, 510) are connected to each other to close an opening from the main body section (110, 510); a positioning section (140, 640) provided opposite at least one of the inner circumferential surfaces (110b, 122b, 510b, 522b, 622b) of the main body section (110, 510) and the wall section (122, 522, 622), the positioning section (140, 640) is configured to determine a relative position of the main body section (110, 510) and the cover section (120, 520, 620); and a groove section (114, 124, 514, 524) formed on at least one of the inner circumferential surfaces (110b, 122b, 510b, 522b, 622b) of the main body section (110, 510) and the wall section (122, 522, 622), the groove section (114, 124, 514, 524) extending in the circumferential direction, wherein the positioning section (140, 640) is provided opposite an edge (114a, 124a, 514a, 524a) of the groove section (114, 124, 514, 524), characterized in that the opening end section (110a, 510a) of the main body section (110, 510) and the leading The end section (122a, 522a, 622a) of the wall section (122, 522, 622) are connected to each other, and the positioning section (140, 640), which is opposite the edge (114a, 124a, 514a, 524a) is provided by the groove section (114, 124, 514, 524), the relative position of the main body section (110, 510) and the cover section (120, 520, 620) in the radial direction of the main body section (110, 510) is determined.

Description

[0001] The present invention relates to a pressure-resistant device according to the preamble of independent claim 1 and a fluid pressure cylinder. Such a pressure-resistant device is known from US patent 8807016 B2.

[0002] A pressure-resistant device, such as a cylinder within a fluid pressure cylinder and a pressure vessel, can be formed by welding a tubular main body section and a cover section together. For example, a cylinder within a fluid pressure cylinder is formed by welding a cylinder tube and a cylinder head together. A joining section formed during welding may protrude from an inner circumferential surface of the cylinder or vessel. In this case, stress concentration occurs at the root of the protruding section, and there is a possibility that cracks will develop in the joining section from this root. To reduce the stress at the root of the protruding section, it is proposed to form a groove on the inner circumferential surface of the cylinder or vessel (WO 2014 / 184291 A2).

[0003] In the cylinder disclosed in WO 2014 / 184291 A2, an extension section, serving as a positioning section, is provided in a cylinder base. This section is located opposite an inner circumferential surface of the cylinder tube, and the relative positions of the cylinder base and the cylinder tube are defined by the positioning section. A groove extending in the circumferential direction is formed on the inner circumferential surface of the cylinder tube. This groove narrows the force transmission path from the cylinder tube to the cylinder base via a connecting section. As a result, the force transmitted to the inner circumference by the connecting section is reduced, and the stress at the root of the connecting section is decreased, thus improving the durability of the cylinder.

[0004] The further the groove is from the inner circumferential surface of the cylinder and closer to the connecting section, the more the force to be transmitted is reduced to the inner circumference of the connecting section. For this reason, to further improve the durability of the cylinder, the groove is preferably positioned close to the connecting section.

[0005] However, in the cylinder disclosed in WO 2014 / 184291 A2, in order to form the groove from the inner circumferential surface of the cylinder close to the connecting section, it is necessary to make the positioning section of the cylinder base short. If the positioning section is short, the cylinder tube and cylinder base cannot be positioned by the positioning section, and there is a possibility that the forming accuracy of the pressure-resistant device will be reduced.

[0006] The object of the present invention is to provide a pressure-resistant device and a fluid pressure cylinder, wherein the forming accuracy and durability of a pressure-resistant device are improved. This object is achieved according to the invention by a pressure-resistant device with the features of independent claim 1. Furthermore, the aforementioned object is achieved by a fluid pressure cylinder with the features of claim 6. Preferred embodiments are set forth in the dependent claims. Description of the drawings Fig. Figure 1 is a sectional view of parts of a hydraulic cylinder comprising a cylinder according to a first embodiment of the present invention. Fig. Figure 2 is an enlarged view of an A-section in Fig. 1. Fig. Figure 3 is a view showing the force flow that is to be transferred from a cylinder base to a cylinder tube when the cylinder is subjected to a tensile load (field lines), according to Fig. 2. Fig. Figure 4 is an enlarged sectional view of a cylinder according to a second embodiment of the present invention. Fig. Figure 5 is an enlarged sectional view of a cylinder according to a third embodiment of the present invention. Fig. Figure 6 is an enlarged sectional view of a cylinder according to a fourth embodiment of the present invention. Fig. Figure 7 is an enlarged sectional view of a cylinder according to a fifth embodiment of the present invention. Fig. Figure 8 is an enlarged sectional view of a cylinder according to a sixth embodiment of the present invention. Description of exemplary implementations

[0007] A pressure-resistant device according to exemplary embodiments of the present invention is described below with reference to the drawings. The pressure-resistant device is designed to be able to store a fluid and absorbs pressure from the fluid on its inner surface. A case in which the pressure-resistant device is a cylinder 100, 200, 300, 400, 500, or 600 used in a hydraulic cylinder 1, which serves as a fluid pressure cylinder, is described below. <Erstes Ausführungsbeispiel>

[0008] First of all, the cylinder 100 according to the first embodiment of the present invention and the hydraulic cylinder 1 with reference to Fig. 1 to 3 described. As in Fig. As shown in Figure 1, the hydraulic cylinder 1 comprises the hollow cylinder 100, a piston rod 20 inserted into the cylinder 100, and a piston 30 provided at an end section of the piston rod 20 and configured to slide along an inner circumferential surface of the cylinder 100. The interior of the cylinder 100 is divided into a rod-side chamber 4 and a counter-rod-side chamber 5 by the piston 30. Working oils, serving as working fluids, are loaded into the rod-side chamber 4 and the counter-rod-side chamber 5.

[0009] The piston rod 20 extends from the cylinder 100, and the hydraulic cylinder 1 is extended and retracted by the working oils supplied to and drained from the cylinder 100. Specifically, when the working oil is supplied to the counter-rod side chamber 5 and the working oil is drained from the rod side chamber 4, the cylinder 1 is extended. When the working oil is supplied to the rod side chamber 4 and the working oil is drained from the counter-rod side chamber 5, the hydraulic cylinder is retracted.

[0010] The cylinder 100 comprises a cylinder tube (tubular main body section) 110 and a cylinder base (cover section) 120, configured to close one opening of the cylinder tube 110. The other opening of the cylinder tube 110 is closed by a cylinder head 50, which is configured to slidably support the piston rod 20. The cylinder base 120 is provided with a mounting section 123 for attaching the hydraulic cylinder 1 to another device.

[0011] In the following, the direction along the central axis of the cylinder tube 110 is referred to as the "axial direction", the direction of radiation from the central axis of the cylinder tube 110 is referred to as the "radial direction", and the direction along the circumference from the central axis of the cylinder tube 110 is referred to as the "circumferential direction".

[0012] Fig. Figure 2 is an enlarged view of an A-section in Fig. 1. As in Fig. As shown in Figure 2, the cylinder base 120 has a base body 121 configured to cover the opening of the cylinder tube 110, and an annular wall section 122 extending axially from the base body 121. A leading end section 122a of the wall section 122 is welded to an opening end section 110a of the cylinder tube 110. In other words, the cylinder tube 110 and the cylinder base 120 are connected to each other via a connecting section 130 formed between the leading end section 122a of the wall section 122 and the opening end section 110a of the cylinder tube 110. For this welding, a random process such as arc welding, which includes plasma welding and TIG welding, gas welding, laser welding, electron beam welding, electric resistance welding, and friction welding can be used.

[0013] The cylinder 100 also includes a support ring 140, which serves as a positioning section configured to determine the relative positions of the cylinder tube 110 and the cylinder base 120. The support ring 140 is designed to be positioned opposite an inner circumferential surface 110b of the cylinder tube 110 and an inner circumferential surface 122b of the wall section 122.

[0014] The support ring 140 is designed to be separate from the cylinder tube 110 and the wall section 122 in a state where the cylinder tube 110 and the wall section 122 are not connected. At the time of connection, the support ring 140 is inserted into both the cylinder tube 110 and the wall section 122. This prevents relative movement between the cylinder tube 110 and the cylinder base 120 during the connection process. Thus, it is possible to connect the cylinder tube 110 and the wall section 122 in a state where the axis of the cylinder tube and the axis of the wall section are aligned.

[0015] The cylinder tube 110 and the wall section 122 are welded together so that the connecting section 130 reaches the inner circumference of the cylinder tube 110 and the wall section 122. Therefore, an outer circumferential surface 140a of the support ring 140 is connected to the connecting section 130. In the example shown in Fig. 2, only a part of the outer circumferential surface 140a is connected to the support ring 140 and the connecting section 130. However, the entire outer circumferential surface 140a can be connected to the support ring 140 and the connecting section 130.

[0016] In the cylinder 100, where the cylinder tube 110 and the cylinder base 120 are connected, the connecting section 130 can project from the inner circumferential surface 110b of the cylinder tube 110 and from the inner circumferential surface 122b of the wall section 122. Even if the support ring 140 is provided on the inner circumference of the connecting section 130, the connecting section 130 can project slightly towards the support ring 140. In such a case, roots 110c, 122c of projecting sections are formed in the connecting section 130. Stress concentration occurs readily at these roots 110c, 122c when the cylinder 100 is subjected to a tensile load in the axial direction.

[0017] In the cylinder 100, to reduce the stress at the roots 110c, 122c, an annular groove section 124, extending in the circumferential direction, is formed on the inner circumferential surface 122b of the wall section 122. In particular, the groove section 124 is designed to have an arc-shaped section such that a maximum inner diameter D3 of the groove section 124 is larger than an inner diameter D1 of the leading end section 122a of the wall section 122 and an inner diameter D2 of the opening end section 110a of the cylinder tube 110. Hereinafter, the maximum inner diameter D3 of the groove section 124 will simply be referred to as the "inner diameter D3 of the groove section 124".

[0018] Fig. Figure 3 is a view that shows a force flow (field lines) to be transmitted from the cylinder base 120 to the cylinder tube 110 when the cylinder 100 is subjected to a tensile load in the axial direction. Fig. 2. In Fig. Figure 3 shows the field lines as broken lines, and diagonal lines indicating sections of the cylinder tube 110, the cylinder base 120, and the connecting section 130 have been omitted. The tensile load acts on the cylinder 100, for example, through pressure from the working oils in the cylinder 100 and a load coupled to the hydraulic cylinder 1.

[0019] When the cylinder 100 receives the tensile load in the axial direction, a force acting on the cylinder base 120 is transmitted to the cylinder tube 110 through the connecting section 130. At this point, the force path through the groove section 124 is restricted. Since the inner diameter D3 of the groove section 124 is larger than the inner diameter D1 of the leading end section 122a of the wall section 122 and the inner diameter D2 of the opening end section 110a of the cylinder tube 110, the force to the cylinder tube 110 is transmitted mainly via a radial outer area of ​​the connecting section 130. Therefore, it is possible to reduce the force transmitted to the inner circumference of the connecting section 130 and to reduce the stress at the roots 110c and 122c of the connecting section 130.This makes it possible to prevent breakage of the roots 110c, 122c, and it makes it possible to improve the durability of the cylinder 100.

[0020] The groove section 124 is preferably formed close to the connecting section 130. This is done because the force acting on the cylinder base 120 passes between the outer circumference and the groove section 124 in the wall section 122, and then through the connecting section 130, while being distributed radially inwards and then transmitted to the cylinder tube 110. Furthermore, because the groove section 124 is formed closer to the connecting section 130, the force to be transmitted from the connecting section 130 to an inner circumferential surface can be further reduced.

[0021] As in Fig. As shown in Figure 2, the support ring 140 in the cylinder 100 is positioned opposite an edge 124a of the groove section 124 on the side of the connecting section 130. Specifically, the position of an edge on the outer circumferential surface 140a of the support ring 140 aligns with the position of the edge 124a of the groove section 124. Therefore, the groove section 124 is formed in the wall section 122 without any axial clearance from the support ring 140. This allows the length of the support ring 140 to be increased in the axial direction, while the groove section 124 is positioned close to the connecting section 130. Furthermore, it is possible to reduce the stress on the inner circumference of the connecting section 130 while maintaining the positioning accuracy of the cylinder tube 110 and the cylinder base 120. This makes it possible to train the cylinder 100 with high accuracy and improved durability.

[0022] The position of the edge of the outer circumferential surface 140a of the support ring 140 corresponds to the position of the edge 124a of the groove section 124. Thus, the entire outer circumferential surface 140a of the support ring 140 is aligned with the inner circumferential surface 110b of the cylinder tube 110 and the inner circumferential surface 122b of the wall section 122. Therefore, it is possible to join the cylinder tube 110 and the wall section 122 in a state where the axis of the cylinder tube and the axis of the wall section align with high precision.

[0023] The groove section 124 has an inner surface formed with first and second curved surface sections 124b, 124c, which have different radii of curvature. In particular, the first curved surface section 124b is formed in a curved surface from a bottom section 124d of the groove section 124 to the edge 124a, and the second curved surface section 124c is formed in a curved surface from the bottom section 124d to the opposite side from the edge 124a.

[0024] The radius of curvature of the first curved surface section 124b is smaller than the radius of curvature of the second curved surface section 124c. Therefore, the gap between the edge 124a and the bottom section 124d of the groove section 124 is smaller than in a case where the radius of curvature of the first curved surface section 124b is not smaller than the radius of curvature of the second curved surface section 124c. Thus, it is possible to form the bottom section 124d close to the connecting section 130 without bringing the edge 124a close to the connecting section 130, and it is possible to further reduce the stress in the inner circumference of the connecting section 130 while maintaining the positioning accuracy of the cylinder tube 110 and the cylinder base 120. This makes it possible to manufacture the cylinder 100 with high accuracy and further improved durability.

[0025] In the cylinder 100, the support ring 140 is formed separately from the cylinder tube 110 and the cylinder base 120, and is positioned opposite the inner circumferential surface 110b of the cylinder tube 110 and the inner circumferential surface 122b of the wall section 122. This reduces heat transfer from the cylinder tube 110 and the cylinder base 120 to the support ring 140 during welding. Consequently, softening of the support ring 110 due to temperature increases is prevented, and protrusion of the joint section 130 is reduced. This mitigates stress concentration in the joint section 130 and further improves the durability of the cylinder 100.

[0026] The groove section 124 is formed on the inner circumferential surface 122b of the wall section 122. Thus, the strength of the wall section 122 is lower than it would be without the groove section 124. Therefore, if the cylinder tube 110 is deformed due to tensile or compressive stress from the working oil in the cylinder 100, the wall section 122 can deform in accordance with the deformation of the cylinder tube 110. This makes it possible to mitigate stress concentrations occurring at the roots 110c, 122c of the connecting section 130.

[0027] When the cylinder tube 110 is deformed by the pressure of the working oils in the cylinder 100, a point of deflection at the base of the wall section 122 on the bottom of the main body 121 becomes a bearing point. The groove section 124 is formed at a corner section between the wall section 122 and the bottom of the main body 121, and the strength at the base of the wall section 122 is low. Therefore, it is possible to deform the wall section 122 more easily in accordance with the deformation of the cylinder tube 110. Thus, it is possible to further mitigate the stress concentration that occurs at the roots 110c, 122c of the connecting section 130.

[0028] The groove section 124 is formed via the inner circumferential surface 122b of the wall section 122 and an end surface 121a of the base body 121. That is, the inner surface of the groove section 124 and the end surface 121a of the base body 121 merge seamlessly without any intervening angle. Therefore, it is possible to increase the radius of curvature of the groove section 124 and to mitigate stress concentrations within the groove section 124.

[0029] According to the first embodiment as described above, the following effects are confirmed.

[0030] In the cylinder 100, the support ring 140 is positioned opposite the edge 124a of the groove section 124. This allows the length of the support ring 140 to be extended while the groove section 124 is brought closer to the connecting section 130. Therefore, the cylinder tube 110 and the cylinder base 120 can be positioned with high accuracy during joining, and the stress concentration in the inner circumference of the connecting section 130 can be reduced after joining. This enables the cylinder 100 to be formed with high accuracy and improves its durability.

[0031] In the cylinder 100, the entire outer circumferential surface 140a of the support ring 140 is opposite the inner circumferential surface 110b of the cylinder tube 110 and the inner circumferential surface 122b of the wall section 122. Therefore, it is possible to align the axis of the cylinder tube 110 and the axis of the wall section 122 with greater precision at the time of joining.

[0032] In the cylinder 100, the support ring 140 is formed separately from the cylinder tube 110 and the cylinder base 120 and is positioned opposite the inner circumferential surface 110b of the cylinder tube 110 and the inner circumferential surface 122b of the wall section 122. This prevents the support ring 140 from softening during welding and reduces the projection of the joint section 130. As a result, the stress concentration in the joint section 130 is mitigated, further improving the durability of the cylinder 100.

[0033] The radius of curvature of the first curved surface section 124b is smaller than the radius of curvature of the second curved surface section 124c. Therefore, it is possible to form the bottom section 124d close to the connecting section 130 without bringing the edge 124a close to the connecting section 130. Consequently, it is possible to further reduce the stress in the inner circumference of the connecting section 130, and it is possible to form the cylinder 100 with higher accuracy and further improved durability. <Zweites Ausführungsbeispiel>

[0034] Next, the cylinder 200 is described in accordance with the second embodiment of the present invention with reference to Fig. 4 described. The same configurations as in cylinder 100 according to the first embodiment are given the same reference numerals and are not described. A hydraulic cylinder to which cylinder 200 can be applied is essentially the same as hydraulic cylinder 1, shown in Fig. 1. Therefore, the hydraulic cylinder is not shown in the figure.

[0035] In the cylinder 200, a support ring 140 with an edge 124a overlaps a groove section 124. In particular, the support ring 140 extends beyond the edge 124a of the groove section 124 and reaches to the opposite side of a connecting section 130.

[0036] In cylinder 200, just as in cylinder 100, the groove section 124 is formed in a wall section 122 without any space from the support ring 140 in the axial direction. Therefore, it is possible to form cylinder 200 with high accuracy and improve its durability.

[0037] Although not shown, first and second curved surface sections, which have different radii of curvature from each other, can be formed on an inner surface of the groove section 124, just as the groove section 124 can be formed on the cylinder 100. <Drittes Ausführungsbeispiel>

[0038] Next, the cylinder 300 is described in accordance with the third embodiment of the present invention with reference to Fig. 5 described. The same configurations as in cylinder 100 according to the first embodiment are given the same reference numerals and are not described. A hydraulic cylinder to which cylinder 300 is applicable is essentially the same as hydraulic cylinder 1, shown in Fig. 1. Therefore, the hydraulic cylinder is not shown in the figure.

[0039] In cylinder 300, instead of the groove section 124 (see Fig. 2) According to the first embodiment, a groove section 114 is formed on an inner circumferential surface 110b of the cylinder tube 110. A support ring 140 is provided opposite an edge 114a of the groove section 114 on the connecting section 130 side. In particular, a section of an edge of an outer circumferential surface 140a of the support ring 140 aligns with a position of the edge 114a of the groove section 114.

[0040] In the cylinder 300, the groove section 114 is formed in the cylinder tube 110 without any axial clearance from the support ring 140. Therefore, it is possible to manufacture the cylinder 300 with high precision and improve its durability.

[0041] Although not shown, the support ring 140 can overlap the edge 114a of the groove section 114. Likewise, the groove section 124 (see Fig. 2) The cylinder 100 can have first and second curved surface sections, which have different radii of curvature, formed on an inner surface of the groove section 114. Additionally, a groove section 124 (see Fig. 2) or a groove section 124 (see Fig. 4) be formed on an inner circumferential surface 122b of a wall section 122. <Viertes Ausführungsbeispiel>

[0042] Next, the cylinder 400 is described in accordance with the fourth embodiment of the present invention with reference to Fig. 6 described. The same configurations as in cylinders 100 and 300 according to the first and third embodiments are given the same reference numerals and are not described. A hydraulic cylinder to which cylinder 400 is applicable is essentially the same as the hydraulic cylinder shown in Fig. 1. Therefore, the hydraulic cylinder is not shown in the figure.

[0043] In cylinder 400, instead of the groove sections 124, 114 (see Fig. 2 and Fig. 5) In the cylinders 100, 300 according to the first and third embodiments, groove sections 114, 124 are formed on an inner circumferential surface 110b of the cylinder tube 110 and on an inner circumferential surface 122b of a wall section 122 of a cylinder base 120. A support ring 140 is provided to cover the groove sections 114, 124.

[0044] In the cylinder 400, the groove sections 114 and 124 are formed in the cylinder tube 110 and in the wall section 122 of the cylinder base 120, without any axial clearance from the support ring 140. Therefore, it is possible to manufacture the cylinder 400 with high accuracy and improve its durability.

[0045] The support ring 140 is designed to cover the groove sections 114 and 124. Therefore, the support ring 140 is also positioned opposite a region of the inner circumferential surface 110b on the side of a connecting section 130 with respect to the groove section 114. Similarly, the support ring 140 is also positioned opposite a region of the inner circumferential surface 122b on the side of the connecting section 130 with respect to the groove section 124. This allows the cylinder tube 110 and the cylinder base 120 to be positioned over a wide area of ​​an outer circumferential surface 140a of the support ring 140. Thus, it is possible to connect the cylinder tube 110 and the wall section 122 in such a way that the axis of the cylinder tube and the axis of the wall section align with high precision.

[0046] Although the groove sections 114 and 124 are formed in the cylinder 400, only groove section 114 or groove section 124 may be formed. Likewise, groove section 124 (see Fig. 2) of the cylinder 100, first and second curved surface sections, which have different radii of curvature from each other, are formed on the inner surface of the groove sections 114, 124. <Fünftes Ausführungsbeispiel>

[0047] Next, the cylinder 500 is described according to the fifth embodiment of the present invention with reference to Fig. 7 described. The same configurations as in cylinders 100 and 300 according to the first and third embodiments are given the same reference numerals and are not described. A hydraulic cylinder to which cylinder 500 is applicable is essentially the same as hydraulic cylinder 1, shown in Fig. 1. Therefore, the hydraulic cylinder is not shown in the figures.

[0048] In the cylinder 500, a cylinder tube 510 has a main tube body 511 which accommodates a piston 30 (see Fig. 1) and a ring section 512, which extends in a ring shape in the axial direction from one end of the main tube body 511. An inner diameter of the main tube body 511 corresponds to a so-called cylinder diameter, and an inner diameter of the ring section 512 is larger than the inner diameter of the main tube body 511.

[0049] A leading end section of the annular section 512 is an opening end section 510a of the cylinder tube 510, and an opening of the cylinder tube 510 is formed by the leading end section of the annular section 512. That is, the annular section 512 is connected to a wall section 522 of a cylinder base 520 by welding. In other words, the cylinder tube 510 and the cylinder base 520 are connected to each other via a connecting section 130 formed between a leading end section 522a of the wall section 522 and the opening end section 510a of the cylinder tube 510. Any welding process, such as arc welding (including plasma welding and TIG welding), gas welding, laser welding, electron beam welding, electric resistance welding, and friction welding, can be used for this welding.

[0050] A support ring 140 is provided opposite an inner circumferential surface 510b of the ring section 512 of the cylinder tube 510 and an inner circumferential surface 522b of the wall section 522. Therefore, it is possible to connect the ring section 512 of the cylinder tube 510 and the wall section 522 of the cylinder base 520 in a state in which the axis of the ring section and the axis of the wall section match each other.

[0051] An annular groove section 514, extending in the circumferential direction, is formed on the inner circumferential surface 510b of the annular section 512, and an annular groove section 524, extending in the circumferential direction, is formed on the inner circumferential surface 522b of the wall section 522. The positions of an edge of an outer circumferential surface 140a of the support ring 140 correspond to the positions of edges 514a, 524a of the groove sections 514, 524 on the connecting section 130 side. Therefore, it is possible to form the cylinder 500 with high accuracy and improve its durability.

[0052] Although not shown, the support ring 140 can be designed to overlap the edges 514a, 524a of the groove sections 514, 524. The support ring 140 can be designed to cover the groove sections 514, 524. Furthermore, as well as the groove section 124 (see Fig. 2) of the cylinder 100, first and second curved surface sections, which have different radii of curvature from each other, can be formed on inner surfaces of the groove sections 514, 524.

[0053] The cylinder 500 is not limited to the mode in which the groove section 514 and the groove section 524 are both formed on the inner circumferential surface 510b of the ring section 512 and on the inner circumferential surface 522b of the wall section 522. The groove section 514 can also be formed only on the inner circumferential surface 510b of the ring section 512, and no groove section 524 can be formed on the inner circumferential surface 522b of the wall section 522. Alternatively, the groove section 524 can also be formed only on the inner circumferential surface 522b of the wall section 522, and no groove section 514 can be formed on the inner circumferential surface 510b of the ring section 512. <Sechstes Ausführungsbeispiel>

[0054] Next, a cylinder 600 is described according to the sixth embodiment of the present invention with reference to Fig. 8 described. The same configurations as in cylinder 100 according to the first embodiment are given the same reference numerals and are not described. A hydraulic cylinder to which cylinder 600 is applicable is essentially the same as hydraulic cylinder 1 shown in Figure 8. Fig. 1. Therefore, the hydraulic cylinder is not shown in the figure.

[0055] Instead of the support ring 140 (see Fig. 2) In contrast to the first embodiment, the cylinder 600 includes a support section 640, which serves as a positioning section, integrated with a wall section 622 of a cylinder base 620.

[0056] The support section 640 is formed separately from a cylinder tube 110 in a state where the cylinder tube 110 and the wall section 622 are not connected. At the time of joining the cylinder tube 110 and the wall section 622, the support section 640 is inserted into the cylinder tube 110. This makes it possible to prevent relative movement between the cylinder tube 110 and the cylinder base 620 at the time of joining. Thus, it is possible to join the cylinder tube 110 and the wall section 622 in a state where the axis of the cylinder tube and the axis of the wall section align.

[0057] Since the support section 640 and the wall section 622 are integrated, it is possible to prevent the support section 640 from moving relative to the wall section 622 when it is inserted into the cylinder tube 110. Therefore, it is possible to easily connect the cylinder tube 110 and the wall section 622 and simply manufacture the cylinder 600.

[0058] A connecting section 130 reaches the inner circumference of the cylinder tube 110. Therefore, an outer circumferential surface 640a of the support section 640 is connected to the connecting section 130. In the example shown in Fig. 8, only a part of the outer circumferential surface 640a is connected to the support section 640 and the connecting section 130. However, the entire outer circumferential surface 640a can be connected to the support section 640 and the connecting section 130.

[0059] An annular groove section 114, extending in the circumferential direction, is formed on an inner circumferential surface 110b of the cylinder tube 110. An edge on the outer circumferential surface 640a of the support section 640 aligns with an edge 114a of the groove section 114 on the connecting section 130 side. Therefore, the groove section 114 is formed in the cylinder tube 110 without any axial clearance from the support section 640. Thus, without reducing the size of the support section 640 in the axial direction, it is possible to form the groove section 114 close to the connecting section 130. This allows for the cylinder 600 to be manufactured with high accuracy and its durability to be improved.

[0060] An annular groove section 624 is formed on an inner circumferential surface 622b of the wall section 622. The inner diameter D3 of the groove section 624 is larger than the inner diameter D2 of the opening end section 110a of the cylinder tube 110. Therefore, it is possible to reduce the force transmitted to the inner circumference of the connecting section 130 through the groove section 624, and it is possible to reduce stress at the root 110c of the connecting section 130. This makes it possible to prevent fractures at the root 110c and to improve the durability of the cylinder 600.

[0061] Although not shown, the support section 640 may be designed to overlap the edge 114a of the groove section 114. The support section 640 may be designed to cover the groove section 114. Furthermore, the same applies to the groove section 124 (see Fig. 2) of the cylinder 100, first and second curved surface sections, which have different radii of curvature from each other, can be formed on an inner surface of the groove section 114.

[0062] The support section 640 can be integrated with the cylinder tube 110 instead of the wall section 622. In this case, an opening from the cylinder tube 110 through the cylinder base 120 is shown in Fig. 2, instead of the cylinder bottom 620, closed, and the position of the edge 124a of the groove section 124 matches a position of an edge of the outer circumferential surface 640a of the support section 640, which is integrated with the cylinder tube 110.

[0063] The configurations, operations, and effects of the exemplary embodiments of the present invention are described below.

[0064] The cylinder 100, 200, 300, 400, 500 or 600 includes the cylinder tube 110 or 510, the cylinder base 120, 520 or 620, which has an annular wall section 122, 522 or 622, the wall section 122, 522 or 622 and the cylinder tube 110 or 510 are connected to each other to close the opening of the cylinder tube 110 or 510, the support ring 140 or the support section 640, provided opposite the inner circumferential surfaces 110b, 122b, 510b, 522b, 622b of the cylinder tube 110 or 510 and the wall section 122, 522 or 622, the support ring or the support section are adapted to the relative positions of the cylinder tube 110 or 510 and the cylinder base 120, 520 or 620 and the groove section 114, 124, 514 or 524, formed on the inner circumferential surface 110b, 122b, 510b, 522b or 622b, the groove section extends in the circumferential direction.The support ring 140 or the support section 640 are provided opposite the edge 114a, 124a, 514a or 524a of the groove section 114, 124, 514 or 524.

[0065] With this configuration, it is possible to extend the length of the support ring 140 or the support section 640, while the groove section 114, 124, 514, or 524 is brought close to the connecting section 130 between the wall section 122, 522, or 622 and the cylinder tube 110 or 510. Therefore, it is possible to position the cylinder tube 110 or 510 and the cylinder base 120, 520, or 620 with high accuracy at the time of joining, and it is possible to reduce the stress in the inner circumference of the connecting section 130 after joining. This makes it possible to improve the forming accuracy and durability of the cylinder 100, 200, 300, 400, 500, or 600.

[0066] In the cylinder 100, 200, 300, 400 or 500, the support ring 140 is formed separately from the cylinder tube 110 or 510 and the cylinder base 120 or 520, and is provided opposite the inner circumferential surfaces 110b, 122b, 510b, 522b of both the cylinder tube 110 or 510 and the wall section 122 or 522.

[0067] With this configuration, heat transfer from the cylinder tube 110 or 510 and the cylinder base 120 or 520 to the support ring 140 is reduced. Therefore, it is possible to prevent softening of the support ring 140 during connection and to reduce protrusion of the connection section 130 between the wall section 122 or 522 and the cylinder tube 110 or 510. This makes it possible to mitigate stress concentration in the connection section 130 and improve the durability of the cylinder 100, 200, 300, 400, or 500.

[0068] In the cylinder 100, 300, 500 or 600, the support ring 140 or the support section 640 is provided, so that the position of the edge of the support ring or the support section matches the position of the edge of the groove section 114, 124, 514 or 524.

[0069] With this configuration, the entire outer circumferential surface 140a or 640a is separated from the support ring 140 or the support section 640 by the inner circumferential surfaces 110b, 510b, 122b, 522b of the cylinder tube 110 or 510 and the wall section 122 or 522.

[0070] Therefore, it is possible to connect the cylinder tube 110 or 510 and the wall section 122 or 522 in a state in which the axis of the cylinder tube and the axis of the wall section match each other with higher accuracy.

[0071] The cylinder 400 includes a support ring 140 to cover the groove section 114 or 124.

[0072] With this configuration, the support ring 140 is also positioned opposite the area of ​​the inner circumferential surface 110b or 122b on the opposite side of the connecting section 130 with respect to the groove section 114 or 124. Therefore, it is possible to further improve the positioning accuracy of the cylinder tube 110 and the cylinder base 120.

[0073] In the cylinder 100, the inner surface of the groove section 124 has the first curved surface section 124b, formed in a curved surface from the bottom section 124d of the groove section 124 to the connecting section 130, and the second curved surface section 124c, formed in a curved surface from the bottom section 124d of the groove section 124 to the opposite side of the connecting section 130, and the radius of curvature of the first curved surface section 124b is smaller than the radius of curvature of the second curved surface section 124c.

[0074] With this configuration, it is possible to bring the bottom section 124d of the groove section 124 close to the connecting section 130 without bringing the edge 124a of the groove section 124 close to the connecting section 130. Therefore, it is possible to further reduce the stress in the inner circumference of the connecting section 130 and to further improve the durability of the cylinder 100.

[0075] The present embodiments relate to hydraulic cylinder 1, adapted to be extended and retracted by supplying and removing working oils to and from the cylinder. The cylinder is cylinder 100, 200, 300, 400, 500 or 600.

[0076] With this configuration, the cylinder is the 100, 200, 300, 400, 500, or 600, as described above. This gives the cylinder high durability. Therefore, it is possible to improve the durability of hydraulic cylinder 1. (1) In the present embodiments, the groove section 114, 124, 514, 524 or 624 is formed around its entire circumference in the circumferential direction. However, the groove section 114, 124, 514, 524 or 624 can be formed in a section in the circumferential direction. (2) The section of the groove section 114, 124, 514, 524 or 624 may be a shape other than an arc shape, for example, a triangular shape, a square shape, etc. The section of the groove section 114, 124, 514, 524 or 624 is preferably formed in an arc shape, and in this case it is possible to mitigate the stress concentration in the groove section 114, 124, 514, 524 or 624. (3) In the above embodiments, the cylinder used in the hydraulic cylinder 1 is described as the pressure-resistant device. The pressure-resistant device is not limited to this, but can be a pressure vessel, such as a tank, for holding a liquid or a gas.

Claims

[1] A pressure-resistant device (100, 200, 300, 400, 500, 600) comprising: a tubular main body section (110, 510) which has an opening end section (110a, 510a); a lid section (120, 520, 620) having an annular wall section (122, 522, 622) with a leading end section (122a, 522a, 622a), the wall section (122, 522, 622) and the main body section (110, 510) are connected to each other to close an opening from the main body section (110, 510); a positioning section (140, 640) provided opposite at least one of the inner circumferential surfaces (110b, 122b, 510b, 522b, 622b) of the main body section (110, 510) and the wall section (122, 522, 622), the positioning section (140, 640) is configured to determine a relative position of the main body section (110, 510) and the cover section (120, 520, 620); and a groove section (114, 124, 514, 524) formed on at least one of the inner circumferential surfaces (110b, 122b, 510b, 522b, 622b) of the main body section (110, 510) and the wall section (122, 522, 622), the groove section (114, 124, 514, 524) extending in the circumferential direction, wherein the positioning section (140, 640) is provided opposite an edge (114a, 124a, 514a, 524a) of the groove section (114, 124, 514, 524), characterized by , that the opening end section (110a, 510a) of the main body section (110, 510) and the leading end section (122a, 522a, 622a) of the wall section (122, 522, 622) are connected to each other, and the positioning section (140, 640), which is opposite the edge (114a, 124a, 514a, 524a) is provided by the groove section (114, 124, 514, 524), the relative position of the main body section (110, 510) and the cover section (120, 520, 620) in the radial direction of the main body section (110, 510) is determined. [2] The pressure-resistant device (100, 200, 300, 400, 500) according to claim 1, characterized by , that the positioning section (140) is formed separately from the main body section (110, 510) and the cover section (120, 520), and is provided opposite to the inner circumferential surfaces (110b, 122b, 510b, 522b) of both the main body section (110, 510) and the wall section (122, 522). [3] The pressure-resistant device (100, 300, 500, 600) according to claim 1, characterized by , that the positioning section (140, 640) is provided so that a position from an edge of the positioning section (140, 640) matches a position from the edge (114a, 124a, 514a, 524a) of the groove section (114, 124, 514, 524). [4] The pressure-resistant device (400) according to claim 1, characterized by , that the positioning section (140) is provided to cover the groove section (114, 124). [5] The pressure-resistant device (100) according to claim 1, characterized by , that an inner surface of the groove section (124) has a first curved surface section (124b) formed in a curved surface from a bottom section (124d) of the groove section (124) to a connecting section (130) between the wall section (122) and the main body section (110), and a second curved surface section (124c) formed in a curved surface from the bottom section (124d) of the groove section (124) to the opposite side of the connecting section (130), and a radius of curvature of the first curved surface section (124b) is smaller than a radius of curvature of the second curved surface section (124c). [6] A fluid pressure cylinder (1) which is extended and retracted by supplying and removing working fluid to and from a cylinder, wherein the cylinder comprises the pressure-resistant device (100, 200, 300, 400, 500, 600) according to claim 1.

Images