Method for manufacturing a solenoid valve and crimping jig

Abstract

To provide a manufacturing method of an electromagnetic valve which enables a cylindrical body to be swaged vertically with high accuracy, and to provide a swaging tool.SOLUTION: An end 62 of a valve case 61 (a second cylindrical body) is fitted in an inner cylindrical surface of a second pressing part 89 of a swaging part 81 of a swaging tool 71 during swaging to position the valve case 61 coaxially with the cylindrical swaging tool 71. The structure allows the end 62 of the valve case 61 to be swaged vertically in a uniform manner over an entire periphery.SELECTED DRAWING: Figure 6

Description

Technical Field

[0005]

[0001] The present invention relates to, for example, a method for manufacturing a solenoid valve used as a damping force adjusting device for a shock absorber and a caulking jig used in the manufacturing method.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a solenoid valve (hereinafter referred to as "conventional manufacturing method") in which, while holding the second case 70 by the caulking jig 90, the caulking portion 13 of the first case 10 is gradually pressed, and finally, the caulking portion 13 of the first case 10 is firmly pressed to caulking-fix the caulking portion 13 of the first case 10 to the flange portion 71 of the second case 70.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional manufacturing method, since there is a radial gap between the outer surface of the first case 10 and the caulking jig 90, the first case 10 is likely to be misaligned with respect to the caulking jig 90 during caulking, and it is difficult to uniformly caulk the caulking portion 13 in the longitudinal direction (direction along the axis) over the entire circumference. Further, due to the gap, there is a risk that the first case 10 bulges in the radial direction when the caulking portion 13 is caulked longitudinally. Furthermore, as shown in FIG. 2 of Patent Document 2, when the opening edge portion of the valve case 41 is expanded, since the outer diameter of the opening edge portion (large diameter portion 50) is larger than the inner diameter of the caulking jig, the valve case 41 cannot be caulked in the longitudinal direction (direction along the axis).

[0005] The object of this invention is to provide a method for manufacturing a solenoid valve and a crimping jig that can crimp a cylindrical body vertically with high precision. [Means for solving the problem]

[0006] The manufacturing method of the solenoid valve of the present invention comprises a first cylindrical body having a groove extending along its circumferential direction on its outer circumference, and a fitting portion provided at the end that fits into the groove. An expanded portion is formed at the opening edge of the end, which widens toward the opening end. A method for manufacturing a solenoid valve comprising a second cylindrical body, comprising the steps of: inserting the first cylindrical body into the second cylindrical body; and crimping the end of the second cylindrical body into the groove using a crimping jig equipped with a crimping part having a first pressing part that covers the outer circumference of the first cylindrical body and extends from the end on the second cylindrical body side toward the first cylindrical body side, a second pressing part connected to the first pressing part and having a different shape from the first pressing part, and a third pressing part connected to the second pressing part and having a different shape from the first pressing part. The first pressing portion is provided on the second cylindrical body side and is formed by a first curved portion that contacts the expanded portion of the second cylindrical body during the crimping process, and a tapered portion connected to the first curved portion that presses the expanded portion of the second cylindrical body radially inward during the crimping process. It is characterized by the following: Furthermore, the crimping jig of the present invention comprises a first cylindrical body having a groove extending along its circumferential direction on its outer circumference, and a fitting portion provided at the end that fits into the groove. An expanded portion is formed at the opening edge of the end, which widens toward the opening end. A crimping jig used in a method for manufacturing a solenoid valve comprising a second cylindrical body, the crimping jig having a first pressing portion that covers the outer circumference of the first cylindrical body and the end of the second cylindrical body and extends from the end on the second cylindrical body side toward the first cylindrical body side, a second pressing portion connected to the first pressing portion and having a different shape from the first pressing portion, and a third pressing portion connected to the second pressing portion and having a different shape from the first pressing portion. The first pressing portion is provided on the second cylindrical body side and is formed by a first curved portion that contacts the expanded portion of the second cylindrical body during the crimping process, and a tapered portion connected to the first curved portion that presses the expanded portion of the second cylindrical body radially inward during the crimping process. The end of the second cylindrical body is crimped to the groove by the crimping portion. [Effects of the Invention]

[0007] According to the present invention, the cylindrical body of the solenoid valve can be crimped vertically with high precision. [Brief explanation of the drawing]

[0008] [Figure 1]This is an explanatory diagram of this embodiment, showing a longitudinal cross-sectional view of a damping force adjustable hydraulic shock absorber with a control valve mounted next to it and equipped with a solenoid valve. [Figure 2] This is an explanatory diagram of this embodiment, illustrating the shape of the end portion and crimping groove of the valve case before crimping. [Figure 3] This is a longitudinal cross-sectional view of the crimping jig according to this embodiment. [Figure 4] This figure shows a magnified view of section A in Figure 3. [Figure 5] This is an explanatory diagram of this embodiment, illustrating the process of crimping the end of a valve case using a crimping jig. [Figure 6] This is an explanatory diagram of this embodiment, illustrating the process of crimping the end of a valve case using a crimping jig. [Figure 7] This is an explanatory diagram of this embodiment, illustrating the process of crimping the end of a valve case using a crimping jig. [Modes for carrying out the invention]

[0009] One embodiment of the present invention will be described with reference to the attached diagram. Here, as an example of a solenoid valve, we will use the damping force adjustment device 31 in the control valve-mounted type damping force adjustment hydraulic shock absorber 1 shown in Figure 1 as an example, and explain the manufacturing method of the damping force adjustment device 31 (solenoid valve) and the crimping jig 71 used in the manufacturing method. For convenience, the vertical direction in Figure 1 will be referred to as the "vertical direction".

[0010] As shown in Figure 1, the shock absorber 1 has a double-tube structure in which a cylinder 2 is provided inside an outer tube 3, and a reservoir 4 is formed between the cylinder 2 and the outer tube 3. A piston 5 is slidably fitted inside the cylinder 2, dividing the inside of the cylinder 2 into two chambers, an upper chamber 2A and a lower chamber 2B. The shock absorber 1 includes a piston rod 6 whose lower end is connected to the piston 5 and whose upper end passes through the upper chamber 2A and protrudes to the outside of the cylinder 2. The piston rod 6 is inserted through a rod guide 7 fitted to the upper end of the cylinder 2. The upper chamber 2A and the outside are sealed by an oil seal 9 attached to a washer 8.

[0011] The piston 5 is provided with an extension passage 11 and a compression passage 12 that connect the upper cylinder chamber 2A and the lower cylinder chamber 2B. The extension passage 11 is provided with a disc valve 13 that opens when the pressure on the upper cylinder chamber 2A side reaches a set pressure, releasing the pressure on the upper cylinder chamber 2A side to the lower cylinder chamber 2B side. The compression passage 12 is provided with a check valve 14 that allows the working fluid to flow from the lower cylinder chamber 2B to the upper cylinder chamber 2A.

[0012] A base valve 10 is provided at the lower end of the cylinder 2, separating the cylinder lower chamber 2B from the reservoir 4. The base valve 10 is provided with an extension passage 15 and a compression passage 16 that connect the cylinder lower chamber 2B and the reservoir 4. The extension passage 15 is provided with a check valve 17 that allows the working fluid to flow from the reservoir 4 to the cylinder lower chamber 2B. The compression passage 16 is provided with a disc valve 18 that opens when the pressure on the cylinder lower chamber 2B side reaches a set pressure, releasing the pressure on the cylinder lower chamber 2B side to the reservoir 4 side. As the working fluid, oil is sealed inside the cylinder 2, and oil and gas are sealed inside the reservoir 4.

[0013] On the outer periphery of the cylinder 2, a separator tube 20 is attached via a pair of upper and lower seal members 19, 19. An annular oil passage 21 is formed between the cylinder 2 and the separator tube 20. A passage 22 that communicates the annular oil passage 21 with the upper chamber 2A of the cylinder is provided on the upper side wall of the cylinder 2. A cylindrical connection port 23 that protrudes toward the right side (outer side in the cylinder diameter direction) in FIG. 1 is provided on the lower side wall of the separator tube 20. A mounting hole 24 is provided on the side wall of the outer tube 3 coaxially with the connection port 23. A cylindrical valve case 61 (second cylinder) is provided on the side wall of the outer tube 3 so as to surround the mounting hole 24.

[0014] As shown in FIG. 5, an end portion 42 of a cylindrical solenoid case 41 (first cylinder) is inserted (fitted) into an end portion 62 (fitting portion) on the opening side of the valve case 61. An annular caulking groove 51 (groove portion) that extends along the circumferential direction thereof is formed on an outer surface 43 of the end portion 42 of the solenoid case 41. In the present embodiment, the solenoid case 41 and the valve case 61 are integrated (joined) by caulking the end portion 62 of the valve case 61 toward the caulking groove 51 of the solenoid case 41. Note that a fixing portion 50 between the solenoid case 41 and the valve case 61 is covered by a cylindrical cover 35 (see FIG. 1).

[0015] As shown in FIG. 1, the end portion 62 of the valve case 61 is formed to have a smaller outer diameter than other portions. In other words, the end portion 62 of the valve case 61 is formed to be thinner than other portions. Here, FIG. 2 shows a state (hereinafter referred to as "fitting state") before the end portion 42 of the solenoid case 41 is fitted into the end portion 62 (fitting portion) of the valve case 61 (second cylinder) and the end portion 62 of the valve case 61 is caulked.

[0016] As shown in FIG. 2, an expanded portion 63 that is expanded so as to incline radially outward of the valve case 61 (the “upper side” in FIG. 2) toward the open end of the valve case 61 is provided at the opening edge portion (tip portion) of the end portion 62 of the valve case 61. The caulking groove 51 includes a bottom portion 52 having a constant outer diameter, a tapered portion 53 whose diameter is expanded from the right end of the bottom portion 52 in FIG. 2 toward the right direction in FIG. 2, a tapered portion 54 whose diameter is expanded from the left end of the bottom portion 52 in FIG. 2 toward the left direction in FIG. 2, and a flange surface 55 provided between the tapered portion 54 and the outer peripheral surface 43 of the solenoid case 41.

[0017] Next, the caulking jig 71 used in the manufacturing method of the damping force adjusting device 31 (solenoid valve) according to the present embodiment will be described. The caulking jig 71 is made of a material such as tool carbon steel. As shown in FIG. 3, it has a large-diameter portion 73 on one side to be mounted on a movable portion (not shown) of a press device, a small-diameter portion 75 on the other side, and a tapered portion 74 connecting the large-diameter portion 73 and the small-diameter portion 75. A caulking portion 81 that opens to the end surface 77 of the small-diameter portion 75 is provided on the inner peripheral surface 76 of the small-diameter portion 75. The caulking portion 81 covers the outer periphery of the end portion 62 of the valve case 61 in the fitted state during caulking.

[0018] As shown in FIG. 4, the caulking portion 81 has a first pressing portion 83 whose open end 84 opens to the end surface 77 of the small-diameter portion 75. The first pressing portion 83 extends along the axis from the open end 84 toward the side opposite to the end surface 77 side (the upper side in FIG. 4, the first cylindrical body side). The inner diameter of the open end 84 of the first pressing portion 83 is set larger than the outer diameter (maximum outer diameter) of the open end of the expanded portion 63 of the valve case 61 (the second cylindrical body). The first pressing portion 83 has a first curved portion 85 provided on the open end 84 side (the lower side in FIG. 4, the second cylindrical body side).

[0019] In the cross-section shown in Figure 4, the first curved portion 85 has a pressing surface (curved surface) that is formed in a convex R shape towards the inside (the "right side" in Figure 4), and extends along the axis so as to decrease in diameter toward the upper side (the first cylindrical body side) in Figure 4. The first pressing portion 83 also has a tapered portion 86 connected to the end of the first curved portion 85 opposite to the open end 84 (the upper side, the first cylindrical body side in Figure 4). The tapered portion 86 extends such that its pressing surface (tapered surface) gradually decreases in diameter along the axis toward the opposite side of the open end 84.

[0020] The crimping portion 81 has a second pressing portion 89 connected to a first pressing portion 83 by a connecting portion 88. The pressing surface (inner cylindrical surface) of the second pressing portion 89 extends along the axis from the connecting portion 88 toward the upper side (first cylindrical body side) in Figure 4 with a constant inner diameter. The inner diameter of the second pressing portion 89 is set to contact (fit with a constant fit) the outer diameter (outer diameter of the cylindrical portion with a constant diameter) of the end portion 62 of the valve case 61.

[0021] The crimping portion 81 has a second curved portion 91 connected to the second pressing portion 89 by a connecting portion 90. The curved surface of the second curved portion 91 is formed in an R shape that is convex outward (to the "left side" in Figure 4) and extends along the axis so as to decrease in diameter toward the upper side (towards the first cylindrical body) in Figure 4. The crimping portion 81 also has a third pressing portion 93 connected to the second curved portion 91 by a connecting portion 92. In other words, the second pressing portion 89 and the third pressing portion 93 are connected by the second curved portion 91. The pressing surface (tapered surface) of the third pressing portion 93 extends so as to decrease in diameter along the axis toward the upper side in Figure 4.

[0022] Next, with reference to Figures 4 to 7, a method for manufacturing the damping force adjustment device 31 (solenoid valve) using a crimping jig 71 will be described. Here, the process of crimping the opening edge of the end portion 62 (fitting portion) of the valve case 61 (second cylindrical body) into the crimping groove 51 (groove portion) of the solenoid case 41 using the crimping jig 71 will be described. For convenience, the vertical direction in Figures 5 to 7 will be referred to as the "vertical direction".

[0023] First, the outer tube 3 is fixed to a fixing jig (not shown), and the end 42 of the solenoid case 41 (first cylindrical body) is fitted into the end 62 (fitting portion) of the valve case 61 (second cylindrical body) which is joined to the outer tube 3. In this fitted state, the solenoid case 41 and the valve case 61 are positioned coaxially with respect to a crimping jig 71 mounted on a press device (not shown). The internal components 33 are pre-assembled into the valve case 61.

[0024] Next, when the crimping jig 71 is lowered (moved along its axis), as shown in Figure 5, first, the first curved portion 85 of the first pressing portion 83 of the crimping portion 81 of the crimping jig 71 comes into contact with the tip of the expanding portion 63 of the end portion 62 of the valve case 61 (second cylindrical body). Then, as the crimping jig 71 is lowered, the tip of the expanding portion 63 is guided radially inward to conform to the curved surface of the first curved portion 85. In this way, the expanding portion 63 is guided radially inward by the first curved portion 85, which prevents the expanding portion 63 from tilting radially outward.

[0025] When the tip of the expanded portion 63 of the end 62 of the valve case 61 passes the first curved portion 85 of the first pressing portion 83, the expanded portion 63 is pressed radially inward by the tapered portion 86 of the first pressing portion 83. As the crimping jig 71 descends, the expanded portion 63, which has tilted radially outward, is gradually raised (deformed) to conform to the tapered surface of the tapered portion 86. As a result, the expanded portion 63 has the same outer diameter as the rest of the end 62. Hereinafter, the deformed expanded portion 63 will be referred to as the tip portion 65. As the crimping jig 71 descends further, as shown in Figure 6, the tip portion 65 of the end 62 of the valve case 61 is fitted into the second pressing portion 89 of the crimping portion 81 of the crimping jig 71.

[0026] As the crimping jig 71 descends further, the tip 65 of the end 62 of the valve case 61 (second cylindrical body) is pressed radially inward to conform to the curved surface of the second curved portion 91, and is gradually tilted radially inward toward the crimping groove 51 (groove portion) of the solenoid case 41 (first cylindrical body) (deforms). At this time, a part of the end 62 of the valve case 61 is fitted into the inner cylindrical surface of the second pressing portion 89, which prevents the end 62 of the valve case 61 from bulging radially outward.

[0027] As the crimping jig 71 descends further, the tip 65 of the end 62 of the valve case 61 (second cylindrical body) is pressed along the axial direction by the tapered surface of the third pressing part 93. As a result, as shown in Figure 7, the opening edge of the valve case 61, including the tip 65 of the end 62, is crimped vertically around the entire circumference into the annular crimping groove 51 (groove) of the solenoid case 41 (first cylindrical body). At this time as well, a part of the end 62 of the valve case 61 is fitted into the inner cylindrical surface of the second pressing part 89, which prevents the end 62 of the valve case 61 from bulging radially outward.

[0028] In conventional crimping methods, a radial gap exists between the outer surface of the second cylindrical body and the crimping jig during crimping. This makes it difficult for the second cylindrical body to become misaligned with the crimping jig, and thus difficult to uniformly crimp the fitting portion of the second cylindrical body vertically around its entire circumference. In contrast, in this embodiment, during crimping, a portion of the end portion 62 of the valve case 61 (second cylindrical body) is fitted to the inner cylindrical surface of the second pressing portion 89 of the crimping portion 81 of the crimping jig 71, thereby positioning the valve case 61 coaxially with respect to the cylindrical crimping jig 71. This allows the opening edge portion of the end portion 62 of the valve case 61 to be crimped uniformly and vertically over its entire circumference.

[0029] Furthermore, in conventional manufacturing methods, due to the radial gap between the outer surface of the second cylindrical body and the crimping jig, when the end of the second cylindrical body was crimped vertically, the end of the second cylindrical body would sometimes bulge radially. In contrast, in this embodiment, during crimping, a portion of the end portion 62 of the valve case 61 (second cylinder) is fitted to the inner cylindrical surface of the second pressing portion 89 of the crimping portion 81 of the crimping jig 71, thereby preventing deformation of the end portion 62 of the valve case 61. Thus, in this embodiment, since the end portion 62 of the valve case 61 is not deformed during crimping, it is possible to crimp the end portion 62 of the valve case 61 with a smaller processing force, thereby reducing the load on the outer tube 3. This prevents deformation of the outer tube 3 due to crimping.

[0030] Furthermore, with conventional crimping jigs, if the opening edge at the end of the second cylindrical body is widened, the outer diameter of the opening edge (widened portion) of the second cylindrical body is larger than the inner diameter of the crimping jig, making it impossible to crimp the second cylindrical body vertically (along the axis). In contrast, in this embodiment, the first pressing portion 82 of the crimping portion 81 of the crimping jig 71 is provided with a first curved portion 85 whose inner diameter at the opening end is larger than the outer diameter of the expanding portion 63 of the end 62 of the valve case 61 (second cylindrical body). As a result, the tip of the expanding portion 63 of the end 62 of the valve case 61 first contacts the first pressing portion 82 of the crimping portion 81 of the crimping jig 71 with the first curved portion 85. Then, as the crimping jig 71 moves, the tip of the expanding portion 63 is guided radially inward so as to follow the curved surface of the first curved portion 85 of the first pressing portion 82, thereby preventing the expanding portion 63 from tilting radially outward. [Explanation of Symbols]

[0031] 31 Damping force adjustment device (solenoid valve), 41 Solenoid case (first cylinder), 51 Crimping groove (groove), 61 Valve case (second cylinder), 71 Crimping jig, 81 Crimping section, 83 First pressing section, 89 Second pressing section, 93 Third pressing section

Claims

1. A method for manufacturing a solenoid valve, comprising: a first cylindrical body having a groove extending along its circumferential direction on its outer circumference; and a second cylindrical body having a fitting portion at its end that fits into the groove, and an expanding portion formed at the opening edge of the end that widens toward the opening end; The steps include inserting the first cylindrical body into the second cylindrical body, A step of crimping the end of the second cylindrical body into the groove using a crimping jig equipped with a crimping section having a first pressing section that covers the outer circumference of the first cylindrical body and extends from the end of the second cylindrical body toward the first cylindrical body, a second pressing section connected to the first pressing section and having a different shape from the first pressing section, and a third pressing section connected to the second pressing section and having a different shape from the first pressing section, Equipped with, A method for manufacturing a solenoid valve, characterized in that the first pressing portion is provided on the second cylindrical body side and is formed by a first curved portion that contacts the expanded portion of the second cylindrical body in the crimping step, and a tapered portion connected to the first curved portion that presses the expanded portion of the second cylindrical body radially inward in the crimping step.

2. A method for manufacturing a solenoid valve according to claim 1, A method for manufacturing a solenoid valve, characterized in that the second pressing portion and the third pressing portion are connected by a second curved portion.

3. A crimping jig used in a method for manufacturing a solenoid valve, comprising: a first cylindrical body having a groove extending along its circumferential direction on its outer circumference; and a second cylindrical body having a fitting portion at its end that fits into the groove, and an expanding portion formed at the opening edge of the end that widens toward the opening end; A crimping jig characterized in that the end of the second cylinder is crimped into the groove by a crimping portion formed by a crimping portion which covers the outer circumference of the first cylinder and the end of the second cylinder and extends from the end of the second cylinder toward the first cylinder; a second pressing portion which is connected to the first pressing portion and has a different shape from the first pressing portion; and a third pressing portion which is connected to the second pressing portion and has a different shape from the first pressing portion, wherein the first pressing portion is provided on the side of the second cylinder and has a first curved portion which contacts the expanding portion of the second cylinder in the crimping step, and a tapered portion which is connected to the first curved portion and presses the expanding portion of the second cylinder radially inward in the crimping step.

4. A crimping jig according to claim 3, A crimping jig characterized in that the second pressing portion and the third pressing portion are connected by a second curved portion.

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