Compressor

Abstract

To provide a compressor capable of reducing the cost while suppressing deterioration even when deterioration due to contact with fluid is concerned.SOLUTION: A compressor includes a cylinder 21 having a cylinder chamber 31, a piston 27 reciprocating inside the cylinder 21, a head cover 41 closing one end surface of the cylinder 21, a head cover presser 61, and a fastener 15. The head cover presser 61 is disposed on a side opposite to the cylinder 21 with the head cover 41 as a reference. The fastener 15 connects the head cover presser 61 and the cylinder 21, and energizes the head cover 41 toward the cylinder 21. The head cover 41 is miniaturized by the head cover presser 61, and the cost can be reduced while suppressing deterioration.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a compressor used to compress a fluid such as hydrogen. [Background technology]

[0002] A reciprocating compressor has been proposed in which the end face of the cylinder is blocked by a block, and the block has an intake valve and a discharge valve inside, with a gas inlet and outlet on the opposite side of the compression chamber across the block (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-52709 Summary of the Invention [Problem to be solved by the invention]

[0004] As in Patent Document 1, forming a fluid flow path inside the block may accelerate deterioration of the block due to contact with the fluid. In particular, when the fluid is hydrogen, hydrogen embrittlement must be taken into consideration. To address hydrogen embrittlement, it is suitable to use heat-resistant steel such as SUH660 as the material for the block. However, this type of heat-resistant steel is expensive and difficult to process, which increases the cost of the compressor.

[0005] The surface of the block that comes into contact with the fluid is exposed to high pressure, and if there is a point on this surface where stress is likely to concentrate, there is a risk that the block will break from that point. The present invention provides a compressor that can reduce costs while suppressing deterioration, even when deterioration due to contact with fluid is a concern. [Means for solving the problem]

[0006] A first aspect of the present invention is a cylinder having a cylinder chamber; a piston that reciprocates inside the cylinder; a head cover that closes one end face of the cylinder; a head cover holder disposed on the opposite side of the cylinder with respect to the head cover; a fastener that connects the head cover retainer and the cylinder and urges the head cover retainer and the head cover toward the cylinder; It is a compressor equipped with.

[0007] The cylinder chamber is the space where the fluid is compressed. The center part of the head cover can be configured to fit inside the cylinder. The piston can be driven by any method, such as a hydraulic cylinder or an electric motor.

[0008] The head cover retainer is positioned on the opposite side of the cylinder relative to the head cover. The head cover retainer does not have to contact the cylinder. The head cover retainer and the head cover may be adjacent to each other. Some kind of intervening object may be sandwiched between the head cover retainer and the head cover.

[0009] The fastener is connected to the head cover retainer and biases the head cover retainer toward the cylinder. The head cover is pressed against the head cover retainer and tightly contacts the cylinder. The fastener is, for example, a tie rod. The end of the tie rod is inserted into the head cover retainer.

[0010] The head cover may have a flow path for suction and discharge of the fluid compressed in the cylinder chamber.

[0011] The flow passages in the head cover are holes that connect the cylinder chamber to the outside space. One end of the flow passage opens into the cylinder chamber. The other end opens into the side of the head cover, etc. The flow passages can be arranged freely. The number of flow passages can also be freely determined. Each flow passage can be simply straight, or it can be bent along the way.

[0012] The head cover may have a recess recessed in a direction away from the piston on a surface that opens into the cylinder chamber. The piston may have a protrusion that fits into the recess.

[0013] The recess is a depression created by cutting away a portion of the surface near the center that opens to the cylinder chamber. The recess reduces the difference in thickness between the center and outer edge of the head cover. This reduces the temperature difference between different parts, even during sudden temperature changes, allowing expansion and contraction to proceed smoothly. Furthermore, by opening one end of the flow path to the recess, the extension of the flow path is reduced.

[0014] The convex portion is provided on the tip surface of the piston. When the piston approaches the head cover, the convex portion fits into the concave portion, reducing the minimum volume of the cylinder chamber and promoting the increase in fluid pressure. The concave and convex portions are shaped so as not to interfere with the movement of the piston.

[0015] The recess may have a fillet on the outer edge of the bottom surface. One end of the flow path may be open to the surface of the fillet.

[0016] A fillet is a chamfer provided at the corner between the inner circumferential surface of a recess and the bottom surface of the recess. The fillet connects both surfaces in an arc shape, eliminating sharp corners. The fillet alleviates stress concentration at the outer edge of the bottom surface of the recess when the fluid is compressed.

[0017] One end of the flow path may open to the surface of the fillet. By forming the flow path at a substantially right angle to the surface of the fillet, the flow path will be inclined with respect to the direction of movement of the piston. In this case, the flow path may be bent midway, and the other end of the flow path may open to the side surface of the head cover.

[0018] The flow path may have a connection port at the end remote from the cylinder chamber. In this case, the head cover may have an exhaust hole extending from the inner circumferential surface of the connection port toward the head cover retainer, and the head cover retainer may have a relief groove that connects the exhaust hole to the outside.

[0019] The connection port is provided at a position where the flow path opens to the external space. The connection port is a location for incorporating a check valve or the like. The exhaust hole is formed inside the head cover. One end of the exhaust hole opens to the inner surface of the connection port. The other end opens to the contact surface with the head cover retainer. The relief groove is formed in the contact surface with the head cover of the head cover retainer. The relief groove is positioned in accordance with the exhaust hole to prevent the exhaust hole from being blocked. [Effects of the Invention]

[0020] According to the compressor of the present invention, even when deterioration due to fluid is a concern, the head cover can be made smaller, thereby suppressing deterioration and reducing costs. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a compressor according to a first embodiment; [Figure 2] A perspective view of the head cover in Figure 1 turned upside down. [Figure 3] Vertical cross section of Figure 2 [Figure 4] Assembly diagram of Figure 1 [Figure 5] FIG. 10 is a perspective view of a compressor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] First Embodiment 1 , a compressor 10 of this embodiment includes a drive unit 11, a drive rod 17, a base plate 13, a piston 27, a cylinder 21, a jacket 23, a head cover 41, a head cover retainer 61, a fastener 15, a joint 33, and a check valve 59. The drive unit 11 generates reciprocating motion of the piston 27 using hydraulic pressure or the like as a power source. The piston 27 and the drive unit 11 are connected via the drive rod 17.

[0023] The cylinder 21 is cylindrical. The jacket 23 is cylindrical and surrounds the outside of the cylinder 21. The cylinder 21 and the jacket 23 are aligned concentrically. A gap is secured between the cylinder 21 and the jacket 23. The cylinder 21 and the jacket 23 are placed on the surface of the base plate 13.

[0024] The head cover 41 has a flange portion 43 and a fitting portion 45. The flange portion 43 closes the end faces of the cylinder 21 and the jacket 23. The flange portion 43 has a circular cross section with the same diameter as the jacket 23. The fitting portion 45 protrudes from one end face side of the flange portion 43. The fitting portion 45 is fitted into the inner circumferential surface of the cylinder 21. The space defined by the cylinder 21, the piston 27, and the head cover 41 is the cylinder chamber 31. The fluid to be compressed is, for example, hydrogen.

[0025] A seal 55 is disposed on the outer peripheral surface of the fitting portion 45. The seal 55 seals the gap between the cylinder 21 and the head cover 41. Coolant is supplied between the cylinder 21 and the jacket 23. The jacket 23 has a connection port 25. A fitting 33 is attached to the connection port 25. The fitting 33 serves as an inlet and an outlet for the coolant.

[0026] A recess 47 opens at the end face of the fitting portion 45. The recess 47 is a portion that is recessed in a direction away from the piston 27. The recess 47 reduces the thickness of the center of the head cover 41, thereby reducing the difference in thickness between the center and the outer edge of the head cover 41. If the head cover 41 is heated, the temperature difference between different portions is reduced.

[0027] The head cover 41 has flow paths 51. One end of each flow path 51 opens to the bottom surface of the recess 47, and the other end opens to the side surface of the flange portion 43. A connection port 53 is provided at the opening in the side surface of the flange portion 43. A check valve 59, for example, is attached to the connection port 53. By opening one end of each flow path 51 to the bottom surface of the recess 47, the length of the flow path 51 is shortened, and the effects of exposure to high pressure are reduced.

[0028] A seal 28 is disposed on the outer peripheral surface of the piston 27. The seal 28 is in close contact with the inner peripheral surface of the cylinder 21. The piston 27 has a protrusion 29 on its tip surface. When the piston 27 comes closest to the head cover 41, the protrusion 29 fits into the recess 47, minimizing the volume of the cylinder chamber 31.

[0029] The head cover retainer 61 is disposed on the opposite side of the cylinder 21 with respect to the head cover 41. The head cover retainer 61 has the same shape as the base plate 13. The head cover retainer 61 comes into contact with the head cover 41 and covers the head cover 41. The outer edge of the head cover retainer 61 protrudes from the head cover 41.

[0030] The fastener 15 is arranged to surround the outside of the jacket 23. The fastener 15 extends in the axial direction of the cylinder 21. One end of the fastener 15 is integrated with the base plate 13. The other end is inserted into a fixing hole 63 of the head cover retainer 61. A nut 16 is screwed onto the fastener 15 protruding from the fixing hole 63, thereby urging the head cover retainer 61 toward the cylinder 21. At the same time, the head cover 41 is urged toward the cylinder 21. The urging of the head cover 41 seals the cylinder chamber 31. The fastener 15 is, for example, a tie rod.

[0031] The head cover retainer 61 does not come into contact with the fluid being compressed, and deterioration caused by the fluid is suppressed. There is no need to use expensive materials for the head cover retainer 61. There is no need to consider the connection with the fastener 15 for the head cover 41, and it can be made smaller. Even if an expensive steel material such as SUH660 is used for the head cover 41, costs can be reduced by making it smaller.

[0032] An exhaust hole 57 opens in the connection port 53 at the end of the flow path 51. The exhaust hole 57 extends toward the head cover retainer 61. The head cover retainer 61 has an escape groove 67. The escape groove 67 is arranged on the contact surface with the head cover 41 and communicates with the exhaust hole 57. The exhaust hole 57 opens to the outside via the escape groove 67.

[0033] Figure 2 shows the details of the head cover 41 of Figure 1. In Figure 2, the head cover 41 is turned upside down compared to Figure 1. The head cover 41 has a small-diameter fitting portion 45 and a large-diameter flange portion 43. The fitting portion 45 fits into the inner peripheral surface of the cylinder 21. A recess 47 is hollowed out at the end face of the fitting portion 45, giving the fitting portion 45 a cylindrical shape. A seal 55 is provided on the outer peripheral surface of the fitting portion 45. A flow path 51 opens on the side surface of the flange portion 43. A connection port 53 is provided at the position of this opening.

[0034] Fig. 3 is a vertical cross-sectional view of the head cover 41 of Fig. 2. The recess 47 is a portion hollowed out from the end face of the fitting portion 45 toward the flange portion 43. The corners of the bottom surface of the recess 47 and the inner peripheral surface of the recess 47 are smoothly connected via an arc-shaped fillet 49. The fillet 49 alleviates stress concentration even when the cylinder chamber 31 becomes highly pressurized.

[0035] The two sets of flow paths 51 are arranged opposite each other across the center of the head cover 41. One end of each flow path 51 opens into the fillet 49. The flow paths 51 are formed at approximately right angles to the surface of the fillet 49. Each flow path 51 is bent midway and opens into the side surface of the flange portion 43. An exhaust hole 57 opens into the inner peripheral surface of the connection port 53.

[0036] By forming the flow passage 51 from the surface of the fillet 49, the extending direction of the flow passage 51 has a large crossing angle with respect to the moving direction of the piston 27. Therefore, even when the flow passage 51 is bent midway and extended toward the side surface of the flange portion 43, the crossing angle at the bending point becomes gentle. By making the crossing angle gentle in this way, stress concentration at the bending point of the flow passage 51 is alleviated even when the flow passage 51 is exposed to high pressure.

[0037] 4 is an assembly diagram of FIG. 1. The head cover retainer 61 is pulled to the base plate 13 via the fastener 15. The head cover retainer 61 is in contact with the head cover 41. The head cover 41 is biased against the head cover retainer 61 and closes the cylinder 21 and jacket 23. The head cover 41 has two pairs of flow paths 51 facing each other, one pair of which is responsible for suction of the fluid to be compressed and the other pair of which is responsible for discharge of the compressed fluid.

[0038] One end of each flow path 51 opens to the cylinder chamber 31. A check valve 59 is attached to the other end of each flow path 51. If fluid leaks around the check valve 59, it is released to the outside through the exhaust hole 57 and the relief groove 67, preventing damage to the check valve 59.

[0039] A gap is provided between the cylinder 21 and the jacket 23. Coolant is supplied into this gap to cool the area around the cylinder chamber 31. A joint 33 is attached to the jacket 23. The joint 33 functions as an inlet and outlet for the coolant. When the piston 27 approaches the head cover 41, the protrusion 29 of the piston 27 fits into the recess 47.

[0040] Second Embodiment As shown in Fig. 5, the compressor 110 of this embodiment shows a case where the flow path 51 of the head cover 141 is shortened. The flow path 51 may be extended in the direction of movement of the piston 27. This flow path 51 has the shortest path that simply passes through the flange portion 43. One end of the flow path 51 opens to the fillet 49. The other end has a connection port 53.

[0041] The head cover retainer 161 comes into contact with the head cover 141. To prevent the head cover retainer 161 from blocking the flow path 51, the head cover retainer 161 has a piping hole 65.

[0042] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention, and all technical matters included in the technical ideas described in the claims are the subject of the present invention. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents of the disclosure of this specification, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0043] 10, 110 Compressor 11 Drive unit 13 Base Plate 15 Binding device 16 Nut 17 Drive rod 21 cylinders 23 Jacket 25 Connection port 27 Piston 28 stickers 29 Convex part 31 Cylinder chamber 33 Joints 41, 141 head cover 43 Flange 45 Inset part 47 Recess 49 Fillet 51 Flow path 53 Connection port 55 stickers 57 Exhaust hole 59 Check valve 61, 161 Head cover holder 63 Fixing hole 65 Plumbing hole 67 Undercut

Claims

1. A cylinder having a cylinder chamber, A piston that reciprocates inside the cylinder, A head cover that covers one end face of the cylinder, A head cover retainer is positioned on the opposite side of the cylinder with respect to the head cover, A fastening device that connects the head cover retainer and the cylinder, and biases the head cover retainer and the head cover toward the cylinder, A compressor equipped with the following features.

2. The compressor according to claim 1, wherein the head cover has a passage for drawing in and discharging the fluid compressed in the cylinder chamber.

3. The compressor according to claim 2, wherein the head cover has a recess on the surface that opens into the cylinder chamber that is recessed in a direction away from the piston.

4. The compressor according to claim 3, wherein the piston has a protrusion that fits into the recess.

5. The compressor according to claim 3, wherein the bottom outer edge of the recess has a fillet.

6. The compressor according to claim 5, wherein one end of the flow path is open to the surface of the fillet.

7. In the aforementioned flow path, the end furthest from the cylinder chamber has a connection port, The head cover has an exhaust hole extending from the inner circumferential surface of the connection port toward the head cover retainer. The compressor according to any one of claims 2 to 6, wherein the head cover retainer has a relief groove that connects the exhaust hole to the outside.

Images