JP7390973B2 - buffer - Google Patents

Description

The present invention relates to a shock absorber.

In the shock absorber, a first expansion side communication passage and a second expansion side communication passage are provided in parallel on the piston, a small diameter disc valve that opens and closes the first expansion side communication passage, and a first expansion side communication passage. There is one that is provided with a large-diameter disc valve that opens and closes the communication passage and the second extension side communication passage (for example, see Patent Document 1).

Japanese Unexamined Patent Publication No. 6-185562

By the way, in a shock absorber, there is a desire to increase the damping force in a region where the piston speed is low while suppressing an increase in the damping force in a region where the piston speed is high.

Therefore, an object of the present invention is to provide a shock absorber that can suppress an increase in damping force in a region where the piston speed is high while increasing the damping force in a region where the piston speed is low.

In order to achieve the above object, the shock absorber according to the present invention includes a passage through which a working fluid flows out due to movement of a piston, an inner sheet, and a passage provided outside the inner sheet and between the inner sheet and the passage. an open intermediate sheet, an outer sheet provided outside the intermediate sheet, an inner peripheral part placed on the inner sheet, an outer peripheral part placed on the intermediate sheet, and a space between the inner peripheral part and the outer peripheral part. a disk-shaped first valve in which a low-rigidity portion is formed in an intermediate portion; a retainer provided on the opposite side of the inner seat of the first valve; an inner side placed on the retainer and an outer side placed on the outer seat; and a disk-shaped second valve.

According to the present invention, it is possible to increase the damping force in the region where the piston speed is low while suppressing an increase in the damping force in the region where the piston speed is high.

1 is a sectional view showing a shock absorber according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a main part of the shock absorber according to the embodiment of the present invention, showing a first valve and a second valve in a closed state. FIG. 2 is a plan view showing a low-rigidity disk of a shock absorber according to an embodiment of the present invention. FIG. 3 is a characteristic diagram showing the damping force characteristics of the shock absorber according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of essential parts showing the open state of the first valve and the second valve of the shock absorber according to the embodiment of the present invention. It is a top view which shows the modification 1 of the low-rigidity disk of the shock absorber of embodiment based on this invention. It is a top view which shows the modification 2 of the low-rigidity disk of the shock absorber of embodiment based on this invention. It is a top view which shows the modification 3 of the low-rigidity disk of the shock absorber of embodiment based on this invention. It is a top view which shows the modification 4 of the low rigidity disk of the shock absorber of embodiment based on this invention. It shows a fifth modification of the low-rigidity disk of the shock absorber according to the embodiment of the present invention, in which (A) is a plan view and (B) is a BB sectional view of (A).

Embodiments according to the present invention will be described based on the drawings.

The shock absorber 11 of the embodiment is a shock absorber used in a suspension device of a railway vehicle, a two-wheeled vehicle, a four-wheeled vehicle, etc., and specifically a shock absorber used in a suspension device of a four-wheeled vehicle. As shown in FIG. 1, the shock absorber 11 is a cylinder that has a cylindrical inner cylinder 15 and a bottomed cylindrical outer cylinder 16 that has a larger diameter than the inner cylinder 15 and is provided on the radially outer side of the inner cylinder 15. It is a dual-tube shock absorber equipped with 17. A reservoir chamber 18 is provided between the outer cylinder 16 and the inner cylinder 15.

The outer cylinder 16 has a cylindrical body member 21 and a bottom member 22 that closes one end of the body member 21 in the axial direction, and has an opening on the opposite side of the body member 21 from the bottom member 22. It is now 23. A mounting eye 24 is fixed to the bottom member 22 on the side opposite to the opening 23.

The shock absorber 11 includes an annular valve body 27 provided at one end of the inner cylinder 15 in the axial direction, and an annular rod guide 28 provided at the other end of the inner cylinder 15 and the outer cylinder 16 in the axial direction. have. The valve body 27 constitutes the base valve 30 and has a stepped outer peripheral portion. The rod guide 28 also has a stepped outer peripheral portion, and its large diameter portion is fitted into the body member 21 .

One axial end of the inner cylinder 15 is fitted into a small diameter portion of the outer periphery of a valve body 27, and is engaged with the bottom member 22 of the outer cylinder 16 via this valve body 27. The other end of the inner tube 15 in the axial direction is fitted into a small diameter portion of the outer circumference of a rod guide 28, and is engaged with the body member 21 of the outer tube 16 via the rod guide 28. There is. In this state, the inner cylinder 15 is positioned in the radial direction with respect to the outer cylinder 16. Here, the valve body 27 and the bottom member 22 communicate with the inner cylinder 15 and the outer cylinder 16 via a passage groove 35 formed in the valve body 27. 16, a reservoir chamber 18 is formed.

The shock absorber 11 has an annular rod seal 41 on the opposite side of the rod guide 28 from the bottom member 22 . This rod seal 41 is also fitted into the inner peripheral portion of the body member 21 similarly to the rod guide 28. A locking portion 43 is formed at the end of the body member 21 opposite to the bottom member 22 by plastically deforming the body member 21 inward in the radial direction by crimping such as curling. The rod seal 41 is held between the locking portion 43 and the rod guide 28. The rod seal 41 closes the opening 23 of the outer cylinder 16, and is specifically an oil seal.

The shock absorber 11 has a piston 45 provided within the cylinder 17. The piston 45 is slidably provided in the inner tube 15 of the cylinder 17. The piston 45 divides the interior of the inner cylinder 15 into two chambers, a first chamber 48 and a second chamber 49. The first chamber 48 is provided between the piston 45 in the inner cylinder 15 and the rod guide 28, and the second chamber 49 is provided between the piston 45 in the inner cylinder 15 and the valve body 27. The second chamber 49 is defined from the reservoir chamber 18 by the valve body 27. Inside the cylinder 17, a first chamber 48 and a second chamber 49 are filled with oil as a working fluid, and a reservoir chamber 18 is filled with gas and oil as working fluid.

The shock absorber 11 has a piston rod 51 that has one end inserted into the cylinder 17 and connected to the piston 45, and the other end of which extends from the cylinder 17 to the outside through the opening 23 of the outer cylinder 16. The piston rod 51 has a main shaft portion 52 and a mounting shaft portion 53 having a smaller diameter than the main shaft portion 52, and is inserted into the cylinder 17 with the mounting shaft portion 53 at the beginning. A piston 45 is connected to a mounting shaft portion 53 of the piston rod 51 with a nut 54 . The piston rod 51 extends from the inner cylinder 15 and the outer cylinder 16 to the outside through the rod guide 28 and the rod seal 41 at the main shaft portion 52 . The rod guide 28 slidably supports the piston rod 51. The piston rod 51 moves in the axial direction with respect to the cylinder 17 together with the piston 45.

The rod seal 41 is provided at the end of the cylinder 17 on the side from which the piston rod 51 extends. The rod seal 41 seals between the body member 21 of the outer cylinder 16 and the main shaft portion 52 of the piston rod 51, and prevents the oil in the inner cylinder 15 and the gas and oil in the reservoir chamber 18 from exiting. Control leakage.

A passage 55 and a passage 56 are formed in the piston 45 and extend through the piston 45 in the axial direction. The passages 55 and 56 allow the first chamber 48 and the second chamber 49 to communicate with each other. The shock absorber 11 has a valve mechanism 57 that can open and close the passage 55 on the opposite side of the piston 45 from the bottom member 22 . The shock absorber 11 also has an annular valve mechanism 58 on the bottom member 22 side of the piston 45 that can open and close the passage 56 .

In the valve mechanism 57, the piston rod 51 moves to the contraction side to increase the amount of penetration into the inner cylinder 15 and the outer cylinder 16, and the piston 45 moves in a direction to narrow the second chamber 49, so that the pressure in the second chamber 49 decreases to the second chamber. When the pressure becomes higher than the pressure in the first chamber 48 by a predetermined value or more, the passage 55 is opened to allow the oil in the second chamber 49 to flow into the first chamber 48, and at this time a damping force is generated. In other words, when the piston rod 51 moves to the contraction side and moves the piston 45, the oil fluid flows out into the first chamber 48 in the passage 55. The valve mechanism 57 is a damping force generating mechanism on the compression side. This valve mechanism 57 does not obstruct the flow of oil in the passage 56.

In the valve mechanism 58, the piston rod 51 moves to the extension side to increase the amount of protrusion from the inner cylinder 15 and the outer cylinder 16, and the piston 45 moves in a direction to narrow the first chamber 48, so that the pressure in the first chamber 48 decreases to the second chamber. When the pressure in the chamber 49 becomes higher than the predetermined value, the passage 56 is opened to allow the oil in the first chamber 48 to flow into the second chamber 49, and at this time a damping force is generated. In other words, by moving the piston rod 51 to the extension side and moving the piston 45, the oil fluid flows out into the second chamber 49 in the passage 56. The valve mechanism 58 is a damping force generating mechanism on the extension side. This valve mechanism 58 does not obstruct the flow of oil in the passage 55.

A liquid passage 61 and a liquid passage 62 are formed in the valve body 27 and extend through the valve body 27 in the axial direction. The liquid passages 61 and 62 are capable of communicating the second chamber 49 and the reservoir chamber 18. The base valve 30 has a valve mechanism 65 on the bottom member 22 side of the valve body 27 in the axial direction, which can open and close the liquid passage 61. The base valve 30 also includes a valve mechanism 66 that can open and close the liquid passage 62 on the side of the valve body 27 opposite to the bottom member 22 in the axial direction.

When the piston rod 51 moves to the contraction side and the piston 45 moves in the direction to narrow the second chamber 49, and the pressure in the second chamber 49 becomes higher than the pressure in the reservoir chamber 18 by a predetermined value or more, the base valve 30 is activated by a valve mechanism. 65 opens the liquid passage 61 to allow the oil in the second chamber 49 to flow into the reservoir chamber 18, generating a damping force at this time. In other words, when the piston rod 51 moves toward the contraction side and moves the piston 45, the oil fluid flows out into the reservoir chamber 18 in the fluid passage 61. The valve mechanism 65 is a damping force generating mechanism on the compression side. This valve mechanism 65 does not obstruct the flow of oil in the liquid passage 62.

In the base valve 30, when the piston rod 51 moves to the extension side, the piston 45 moves to the first chamber 48 side, and the pressure in the second chamber 49 becomes lower than the pressure in the reservoir chamber 18, the valve mechanism 66 opens the liquid passage 62. When opened, the oil in the reservoir chamber 18 will flow into the second chamber 49. In other words, when the piston rod 51 moves to the extension side and moves the piston 45, the oil flows out into the second chamber 49 in the liquid passage 62. The valve mechanism 66 is a suction valve that allows the oil to flow from the reservoir chamber 18 into the second chamber 49 without substantially generating damping force. This valve mechanism 66 does not obstruct the flow of oil in the liquid passage 61.

A covered cylindrical cover 71 is attached to the cylinder 17 on the side from which the piston rod 51 projects. The cover 71 covers the opening 23 side of the body member 21 of the cylinder 17 and the rod seal 41.

A locking member 81 is locked to the piston rod 51 at a position between the piston 45 in the inner cylinder 15 and the rod guide 28 . The locking member 81 has an annular shape, and the main shaft portion 52 of the piston rod 51 is inserted into the locking member 81 . The locking member 81 is fixed to the main shaft portion 52 so as to be immovable in the axial direction.

A buffer member 82 is provided on the piston rod 51 at a position between the locking member 81 in the inner cylinder 15 and the rod guide 28 . The buffer member 82 has an annular shape, and the main shaft portion 52 of the piston rod 51 is inserted into the buffer member 82 . The buffer member 82 is in contact with the locking member 81, and when the piston rod 51 moves to a predetermined position on the fully extended side, it comes into contact with the rod guide 28, and is sandwiched between the locking member 81 and the rod guide 28 to provide elasticity. Alleviates impact by deforming.

Next, the expansion side valve mechanism 58, which is the main part of the embodiment, will be explained.
The piston 45 includes a substantially disc-shaped metal piston body 101 attached to the mounting shaft 53 of the piston rod 51, and a synthetic resin piston body 101 that is attached to the outer peripheral surface of the piston body 101 and slides into the inner cylinder 15. It has a sliding contact member 102.

As shown in FIG. 2, the piston body 101 has an insertion hole 100 formed in the radial center thereof and passing through the piston body 101 in the axial direction. A mounting shaft portion 53 of a piston rod 51 is fitted into this insertion hole 100.

The piston body 101 includes an annular main body part 111 to which the sliding member 102 is attached, an annular collar part 112 provided on the second chamber 49 side in the axial direction from the main body part 111, and the main body part 111. It has an annular neck portion 113 that connects the collar portion 112. The outer diameter of the main body portion 111 is larger than the outer diameter of the collar portion 112, and the outer diameter of the collar portion 112 is larger than the outer diameter of the neck portion 113.

The brim portion 112 of the piston body 101 includes an annular inner seat 121 that protrudes in the axial direction on the radially outer side of the insertion hole 100 on the opposite side of the main body portion 111 in the axial direction, and an inner seat. An annular intermediate sheet 122 that protrudes in the axial direction on the radially outer side of the intermediate sheet 121 and an annular outer sheet 123 that protrudes in the axial direction on the radial outer side of the intermediate sheet 122 are formed. .

Here, in the axial direction of the piston body 101, that is, in the axial direction of the piston 45, the distal end surface of the intermediate sheet 122 is located slightly on the opposite side of the main body part 111 from the distal end surface of the inner sheet 121, and the outer sheet The leading end surface of the intermediate sheet 123 is located on the opposite side of the main body portion 111 from the leading end surface of the intermediate sheet 122 . In other words, in the axial direction of the piston 45, the outer sheet 123 has a higher height position in the protruding direction than the intermediate sheet 122, and the intermediate sheet 122 has a slightly higher height position in the protruding direction than the inner sheet 121. It's getting expensive.

A plurality of passage holes 131 are formed in the piston body 101 at intervals in the circumferential direction, one end of which opens between the inner sheet 121 and the intermediate sheet 122 and passes through the passage hole 131 in the axial direction. The passage hole 131 passes through the main body portion 111, the neck portion 113, and the collar portion 112. The plurality of passage holes 131 are connected to each other by an annular recess 132 between the inner sheet 121 and the intermediate sheet 122.

The plurality of passage holes 131 and the annular recess 132 penetrate the piston 45 in the axial direction and form a part of the passage 133 of the passage 56 that passes through the piston 45 and allows the oil to flow between the first chamber 48 and the second chamber 49. It consists of In other words, the piston 45 is provided between the inner sheet 121 and the intermediate sheet 122, which is provided outside the inner sheet 121 and between which the passage portion 133 of the passage 56 opens. It has an outer sheet 123.

Further, in the piston body 101, a plurality of passage holes 135 are formed at intervals in the circumferential direction, one end of which opens at the end of the main body portion 111 on the side of the brim portion 112 and passes through the main body portion 111 in the axial direction. ing. The passage hole 135 is provided outside the passage hole 131 in the radial direction of the piston 45. The passage hole 135 constitutes the above-described passage 55 that passes through the piston 45 in the axial direction and allows the oil to flow between the first chamber 48 and the second chamber 49.

The inner seat 121, intermediate seat 122, and outer seat 123 of the piston body 101 constitute an extension-side valve mechanism 58, which is a main part of the embodiment. The valve mechanism 58 includes a small-diameter disk 141, a low-rigidity disk 142, a retainer disk 143, a retainer disk 144, a large-diameter disk 145, and a valve, which are stacked on the flange-like portion 112 in the axial direction of the piston 45 in order from the flange-like portion 112 side. It has a disk 146, a retainer disk 147, a backup disk 148, and a washer 149.

The small-diameter disk 141, the low-rigidity disk 142, the retainer disks 143, 144, 147, the large-diameter disk 145, the valve disk 146, the backup disk 148, and the washer 149 are all in the shape of a perforated metal disk. The mounting shaft portion 53 of the piston rod 51 is fitted into the inner circumference of each of the small diameter disc 141, low rigidity disc 142, retainer discs 143, 144, 147, large diameter disc 145, valve disc 146, backup disc 148, and washer 149. In this state, at least the inner peripheral side is clamped in the axial direction by the inner seat 121 of the piston body 101 and the nut 54.

The small diameter disk 141 has a flat plate shape with a constant thickness. A fitting hole 151 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the small-diameter disk 141 so as to penetrate in the axial direction at the center in the radial direction. The small diameter disk 141 has an outer diameter slightly larger than the outer diameter of the distal end surface of the intermediate sheet 122 and smaller than the inner diameter of the distal end surface of the outer sheet 123. Small diameter disk 141 abuts inner sheet 121 and intermediate sheet 122 . In other words, the small diameter disk 141 is placed on the inner sheet 121 and the intermediate sheet 122.

A notch 152 is formed on the outer periphery of the small diameter disk 141 so as to traverse the intermediate sheet 122 in the radial direction while being in contact with the intermediate sheet 122 . The notch 152 penetrates the small diameter disc 141 in the axial direction of the small diameter disc 141, in other words, in the thickness direction of the small diameter disc 141. A plurality of notches 152 are formed in the small diameter disk 141 at equal intervals in the circumferential direction thereof. The diameter of the circle connecting the end positions of the plurality of notches 152 closest to the fitting hole 151 in the radial direction of the small diameter disk 141 is larger than the outer diameter of the tip surface of the inner sheet 121, and The diameter is smaller than the inner diameter of the tip surface. The outer peripheral edge 153 of the small diameter disk 141 excluding the notch 152 is arranged on the same circle coaxial with the fitting hole 151 .

A fitting hole 161 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the low-rigidity disk 142 at a radially central portion thereof, passing through the fitting hole 161 in the axial direction. The fitting hole 161 has the same diameter as the fitting hole 151. The outer diameter of the low-rigidity disk 142 is the same as the maximum outer diameter of the small-diameter disk 141 . The outer peripheral edge 162 of the low-rigidity disk 142 is circular and is arranged on the same circle coaxial with the fitting hole 161 over the entire circumference of the low-rigidity disk 142 .

The low-rigidity disk 142 has a flat plate shape with a constant thickness. The low-rigidity disk 142 has a hollow structure in which a through hole 163 is formed that penetrates in the axial direction of the low-rigidity disk 142, in other words, in the thickness direction of the low-rigidity disk 142. As shown in FIG. 3, a plurality of through holes 163 having the same shape are formed in the low-rigidity disk 142, specifically, in three locations. The through holes 163 have an arc shape, in other words, an R shape, and a plurality of through holes 163 are arranged on the same circle coaxial with the fitting hole 161 and the outer peripheral edge 162.

By forming the plurality of arc-shaped through holes 163, the low-rigidity disk 142 has a flat inner plate portion 166 located inside the plurality of through-holes 163, and a plurality of It has a flat outer plate part 167 located outside the through hole 163 and a flat connecting plate part 168 that connects these parts. In the low-rigidity disk 142, the connecting plate portions 168 are provided between adjacent through-holes 163 in the circumferential direction of the low-rigidity disk 142, and the number of connecting plate portions 168 is the same as that of the through-holes 163, specifically, three. It is formed in places.

By forming the plurality of through-holes 163, the low-rigidity disk 142 has lower rigidity than a case where no through-holes 163 are formed, and has lower rigidity than the small-diameter disk 141. The low-rigidity disk 142 is a flat plate that has lower rigidity than the inner plate part 166 and the outer plate part 167 because a plurality of through holes 163 are formed in the portion between the inner plate part 166 and the outer plate part 167. The low rigidity portion 171 has a shape. The low rigidity portion 171 has a plurality of connecting plate portions 168.

The outer diameter of the inner plate portion 166, in other words, the diameter of the circle connecting the edges of the plurality of through holes 163 on the small diameter side in the radial direction of the low-rigidity disk 142 is the outer diameter of the tip surface of the inner seat 121 of the piston 45. is equivalent to In addition, the inner diameter of the outer plate portion 167, in other words, the diameter of the circle connecting the large-diameter end edges of the low-rigidity disks 142 of the plurality of through holes 163 in the radial direction is the same as that of the tip surface of the outer seat 123 of the piston 45. The diameter is smaller than the inner diameter. The inner diameter of the outer plate portion 167 is smaller than the minimum outer diameter of the small-diameter disk 141, that is, the diameter of a circle connecting the end positions of the plurality of notches 152 closest to the fitting hole 151 in the radial direction of the small-diameter disk 141. It has become. The low-rigidity portion 171 between the outer plate portion 167 and the inner plate portion 166 is located on the outer side in the radial direction of the piston 45 than the outer periphery of the distal end surface of the inner sheet 121.

The small-diameter disk 141 and the low-rigidity disk 142 in contact with the small-diameter disk 141 constitute a disk-shaped first valve 177 . The first valve 177 has an inner peripheral portion 175 placed on the inner seat 121 and an outer peripheral portion 176 placed on the intermediate seat 122 . A low-rigidity portion 171 is formed in the first valve 177 at an intermediate portion 178 between an inner circumferential portion 175 and an outer circumferential portion 176 . The first valve 177 opens and closes the passage portion 133 of the passage 56 by seating on and leaving the front end surface of the intermediate seat 122 .

The retainer disk 143 has a flat plate shape with a constant thickness. A fitting hole 181 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the retainer disk 143 at a radially central portion thereof, passing through the fitting hole 181 in the axial direction. The fitting hole 181 has the same diameter as the fitting hole 151. The outer diameter of the retainer disk 143 is equal to the outer diameter of the front end surface of the inner sheet 121. Therefore, the outer diameter of the retainer disk 143 is equal to the outer diameter of the inner plate portion 166 of the low-rigidity disk 142. The retainer disk 143 abuts against the inner plate portion 166 of the low-rigidity disk 142. The outer peripheral edge of the retainer disk 143 is circular, and is arranged on the same circle coaxially with the fitting hole 181 over the entire circumference of the retainer disk 143.

Retainer disk 144 is the same common component as retainer disk 143. Retainer disk 144 abuts retainer disk 143. The retainer disks 143 and 144 constitute a retainer 185 provided on the opposite side of the first valve 177 from the inner seat 121.

The large diameter disk 145 has a flat plate shape with a constant thickness. A fitting hole 191 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the large-diameter disk 145 at a radially central portion thereof, passing through the fitting hole 191 in the axial direction. The fitting hole 191 has the same diameter as the fitting hole 151. The large diameter disk 145 has an outer diameter slightly larger than the outer diameter of the distal end surface of the outer sheet 123 and comes into contact with the retainer disk 144 and the outer sheet 123. In other words, large diameter disk 145 rests directly on retainer 185 and outer sheet 123.

A notch 192 is formed on the outer periphery of the large-diameter disk 145 so as to traverse the outer sheet 123 in the radial direction while being in contact with the outer sheet 123 . The notch 192 penetrates the large diameter disk 145 in the axial direction of the large diameter disk 145, in other words, in the thickness direction of the large diameter disk 145. A plurality of notches 192 are formed in the large diameter disk 145 at equal intervals in the circumferential direction thereof. The diameter of the circle connecting the end positions of the plurality of notches 192 closest to the fitting hole 191 in the radial direction of the large-diameter disk 145 is larger than the outer diameter of the retainer disk 144, and the diameter of the circle is larger than the outer diameter of the retainer disk 144. The diameter is smaller than the inner diameter of the The outer circumferential edge 193 of the large-diameter disk 145 excluding the notch 192 is arranged on the same circle coaxial with the fitting hole 191 .

The valve disk 146 has a flat plate shape with a constant thickness. A fitting hole 201 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the valve disk 146 in the radial center thereof and extends through the fitting hole 201 in the axial direction. The fitting hole 201 has the same diameter as the fitting hole 151. The outer diameter of the valve disk 146 is equal to the maximum outer diameter of the large diameter disk 145. The outer circumferential edge 202 of the valve disk 146 is circular and is disposed on the same circle coaxially with the fitting hole 201 over the entire circumference of the valve disk 146. The through hole 163 of the low-rigidity disk 142, in other words, a portion like the low-rigidity portion 171 is not formed in the valve disk 146. Valve disk 146 is a plain disk with no holes other than fitting hole 201.

The large-diameter disk 145 and the valve disk 146 in contact with the large-diameter disk 145 constitute a disk-shaped second valve 205. The second valve 205 has a radially inner portion placed on the retainer 185 and a radially outer portion placed on the outer seat 123. The second valve 205 forms a piston inner chamber 208 with a portion of the brim portion 112 of the piston 45 between the intermediate seat 122 and the outer seat 123, the first valve 177, and the retainer 185. The piston inner chamber 208 is a part of the passage 56, and constitutes the passage 56 together with the passage portion 133. The second valve 205 opens and closes the piston inner chamber 208 of the passage 56 by moving toward and away from the distal end surface of the outer seat 123 . The second valve 205 has an outer diameter larger than the outer diameter of the first valve 177.

The first valve 177 communicates the passage portion 133 of the passage 56 with the piston inner chamber 208 in an open state in which the small diameter disc 141 is seated off the intermediate seat 122, and in a closed state in which the small diameter disc 141 is seated in the intermediate seat 122. Thus, communication between the passage portion 133 and the piston inner chamber 208 is suppressed. The inside of the notch 152 formed in the small diameter disc 141 of the first valve 177 is connected to the passage part 133 and the piston even when the small diameter disc 141 is seated on the intermediate seat 122 and the first valve 177 is in the most closed state of the passage part 133. A first fixed orifice 211 communicates with the inner chamber 208.

The second valve 205 communicates between the piston inner chamber 208 of the passage 56 and the second chamber 49 in an open state in which the large-diameter disk 145 is seated on the outer seat 123, while the large-diameter disk 145 is seated on the outer seat 123. In the closed state, communication between the piston inner chamber 208 and the second chamber 49 is suppressed. Inside the notch 192 formed in the large diameter disc 145 of the second valve 205, even when the large diameter disc 145 is seated on the outer seat 123 and the second valve 205 is in the state where the piston inner chamber 208 is in the most closed state, the inside of the piston is A second fixed orifice 212 connects the chamber 208 and the second chamber 49. The passage area of the second fixed orifice 212 is larger than the passage area of the first fixed orifice 211.

Retainer disk 147 is the same common component as retainer disks 143 and 144. Retainer disc 147 abuts valve disc 146.

A fitting hole 221 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the backup disk 148 in the radial center thereof and extends through the fitting hole 221 in the axial direction. The fitting hole 221 has the same diameter as the fitting hole 151. The outer diameter of the backup disk 148 is larger than that of the retainer disk 147 and slightly larger than the outer diameter of the front end surface of the intermediate sheet 122. Backup disk 148 abuts retainer disk 147. The outer peripheral edge of the backup disk 148 is circular and is arranged on the same circle coaxial with the fitting hole 221 over the entire circumference of the backup disk 148.

The washer 149 is thicker and has higher rigidity than any of the small-diameter disk 141, the low-rigidity disk 142, the retainer disks 143, 144, 147, the large-diameter disk 145, the valve disk 146, and the backup disk 148. A fitting hole 231 into which the mounting shaft portion 53 of the piston rod 51 is fitted is formed in the washer 149 at a radially central portion thereof, passing through the fitting hole 231 in the axial direction. The fitting hole 231 has the same diameter as the fitting hole 151. The washer 149 has an outer diameter larger than the outer diameter of the retainer disk 147 and slightly smaller than the outer diameter of the backup disk 148. Washer 149 abuts backup disk 148 and nut 54 . The outer peripheral edge of the washer 149 is circular, and is arranged on the same circle coaxially with the fitting hole 231 over the entire circumference of the washer 149.

The inner circumferential portion of the small diameter disk 141, the inner plate portion 166 of the low-rigidity disk 142, the retainer disks 143, 144, the inner circumferential portion of the large diameter disk 145, and the inner circumferential portion of the valve disk 146. Then, the retainer disk 147, the inner circumferential side portion of the backup disk 148, and the inner circumferential side portion of the washer 149 are clamped in the axial direction by the inner seat 121 of the piston 45 and the nut 54, and are attached to the piston rod 51. Fixed.

As described above, the valve mechanism 58 includes the inner seat 121, intermediate seat 122, and outer seat 123 of the piston 45, the small diameter disc 141, the low rigidity disc 142, the retainer discs 143, 144, 147, the large diameter disc 145, and the valve disc. 146, a backup disk 148, and a washer 149. Therefore, the valve mechanism 58 includes a first valve 177 and a second valve 205 that open and close the passage 56 in series. The valve mechanism 58 also includes a first fixed orifice 211 and a second fixed orifice 212 that form a part of the passage 56 and are connected in series to constantly communicate the first chamber 48 and the second chamber 49 via the passage 56. have.

In the shock absorber 11, for example, the piston rod 51 is attached to the vehicle body side of the vehicle, and the mounting eyes 24 are attached to the vehicle wheel side, so as to buffer relative vibrations between the vehicle body and the wheels.

In the valve mechanism 58, when the piston rod 51 moves to the extension side and the piston 45 moves to the first chamber 48 side, and the pressure in the first chamber 48 increases, the valve mechanism 58 moves from the first chamber 48 to the second chamber 49 through the passage 56. The oil solution will be poured into the At this time, the first valve 177 and the second valve 205 open and close depending on the piston speed, which is the moving speed of the piston 45 with respect to the cylinder 17.

That is, in the valve mechanism 58, as shown by the solid line in FIG. 4, in a first speed region where the piston speed is lower than a predetermined first threshold value v1, both the first valve 177 and the second valve 205 are in a closed state. Therefore, the passage 56 is a flow path constricted by the first fixed orifice 211 and allows the oil to flow from the first chamber 48 to the second chamber 49 . This generates a damping force characteristic of the orifice.

In addition, the valve mechanism 58 allows the first valve 177 to separate from the intermediate seat 122 and open in a second speed region where the piston speed is higher than the first threshold value v1 and lower than the second threshold value v2, which is higher than the first threshold value v1. However, since the second valve 205 is in the closed state, the passage 56 allows the oil to flow from the first chamber 48 to the second chamber 49 through a flow path constricted by the second fixed orifice 212. As a result, as shown by the solid line in FIG. 4, a damping force having orifice characteristics is generated. Here, the rate of increase in damping force with respect to increase in piston speed in the second speed range is lower than the same rate of increase in the first speed range.

Further, in the third speed region where the piston speed is equal to or higher than the second threshold v2, the first valve 177 is separated from the intermediate seat 122 and remains open, while the second valve 177 remains open. 205 leaves the outer seat 123 and opens the valve. Therefore, the passage 56 allows the oil to flow from the first chamber 48 to the second chamber 49 with the first valve 177 and the second valve 205 open. As a result, as shown by the solid line in FIG. 4, a damping force with valve characteristics is generated.

Here, the rate of increase in damping force with respect to increase in piston speed in the third speed range is lower than the same rate of increase in the second speed range. At this time, since the first valve 177 has the low-rigidity portion 171, it is easily deformed and can be spaced largely apart from the intermediate seat 122 to increase the flow path area. Therefore, it is possible to prevent the first valve 177 from restricting the flow of oil through the passage 56. Therefore, an increase in damping force in the third speed region can be suppressed.

Patent Document 1 mentioned above discloses that the piston is provided with a first growth-side communication passage and a second growth-side communication passage in parallel, a small-diameter disc valve that opens and closes the first growth-side communication passage, and a first growth-side communication passage. A shock absorber is disclosed that includes a large-diameter disc valve that opens and closes a second growth-side communication passage and a second growth-side communication passage. In this shock absorber, a small-diameter disc valve and a large-diameter disc valve are provided in series with respect to the first extension side communication path, so that both the small-diameter disc valve and the large-diameter disc valve open. In the high piston speed range, the small-diameter disc valve acts as a restriction, potentially increasing the damping force.

In contrast, the shock absorber 11 of the embodiment includes an inner sheet 121, an intermediate sheet 122 provided outside the inner sheet 121, and in which a passage portion 133 of the passage 56 opens between the inner sheet 121 and the intermediate sheet 121. An outer sheet 123 is provided on the outside, an inner peripheral portion 175 is placed on the inner sheet 121, an outer peripheral portion 176 is placed on the intermediate sheet 122, and an intermediate portion 178 between the inner peripheral portion 175 and the outer peripheral portion 176 has a low rigidity. A disk-shaped first valve 177 in which a portion 171 is formed, a retainer 185 provided on the opposite side of the inner seat 121 of the first valve 177, and an inner side placed on the retainer 185 and an outer side placed on the outer seat 123. It has a disk-shaped second valve 205. In this way, since the first valve 177 and the second valve 205 are provided in series with the passage 56, and the first valve 177 is provided with the low-rigidity portion 171, the damping force can be increased in the region where the piston speed is low. , it is possible to suppress an increase in damping force in a region where the piston speed is high.

That is, the broken line shown in FIG. 4 is the damping force characteristic of Comparative Example 1 in which the first valve 177 is not provided in the valve mechanism 58 of the embodiment. In Comparative Example 1, the damping force in the very low speed region where the piston speed is lower than the second threshold value v2 is lower than that of the valve mechanism 58 of the embodiment shown by the solid line in FIG. On the other hand, in the embodiment, by providing the first valve 177 in the valve mechanism 58, the damping force in the very low speed region is increased higher than that of Comparative Example 1 shown by the broken line in FIG. 4, as shown by the solid line in FIG. can.

The two-dot chain line shown in FIG. 4 indicates the difference between the second threshold value v2 and above in Comparative Example 2, in which a plain disk with high rigidity is provided in place of the low-rigidity disk 142 of the first valve 177 in the valve mechanism 58 of the embodiment. This is the damping force characteristic in the speed region. In Comparative Example 2, in the very low speed region where the piston speed is lower than the second threshold v2, as shown by the solid line in FIG. 4, the damping force can be made higher than in Comparative Example 1 shown by the broken line in FIG. The damping force in the high speed region equal to or higher than the second threshold value v2, as shown by the two-dot chain line in FIG. 4, becomes significantly higher than that in Comparative Example 1 shown by the broken line in FIG.

In contrast, in the embodiment, by providing the low rigidity portion 171 in the first valve 177 of the valve mechanism 58, the amount of lift from the intermediate seat 122 when the first valve 177 is opened is increased compared to Comparative Example 2. can. Therefore, as shown by the solid line in FIG. 4, the damping force in the high speed region where the piston speed is equal to or higher than the second threshold value v2 can be lowered than in Comparative Example 2 shown by the two-dot chain line in FIG. It is possible to obtain damping force characteristics equivalent to those of Comparative Example 1 shown by the broken line in FIG.

That is, in the embodiment, by providing the first valve 177 in the valve mechanism 58 and providing the low rigidity portion 171 in the first valve 177, the damping force in the very low speed region is made higher than in the case where the first valve 177 is not provided. At the same time, the increase in damping force in the high speed region can be suppressed to the same extent as in the case where the first valve 177 is not provided.

The low-rigidity portion 171 has low rigidity by forming the plurality of through holes 163 in the low-rigidity disk 142, so that the rigidity of the first valve 177 can be greatly reduced, and the first valve 177 can easily have a low rigidity. A rigid portion 171 can be formed.

Further, since the through hole 163 has an arc shape, stress generated in the low rigidity disk 142 of the first valve 177 can be alleviated.

Furthermore, since the low-rigidity portion 171 is located outside the outer periphery of the inner seat 121, the rigidity of the first valve 177 can be significantly reduced.

Note that the lift amount of the first valve 177 can also be suppressed by replacing the retainer disk 143 with a plain disk that has the same outer diameter as the low-rigidity disk 142 and has no through holes other than the fitting hole. In this way, it is possible to adjust the damping force in the high speed range and to alleviate the stress on the low-rigidity disk 142 while maintaining the damping force in the low and medium piston speed ranges.

In addition, by changing at least one of the hollow shape and the number of the through holes 163 of the low-rigidity disk 142 and changing the rigidity, the lift amount of the first valve 177 can be adjusted, and the piston speed is attenuated in a high-speed range. It is possible to adjust the force.

[Modification 1]
For example, instead of the low-rigidity disk 142 described above, a low-rigidity disk 142a of Modification 1 as shown in FIG. 6 may be used. The low-rigidity disk 142a has an inner plate portion 166 and an outer plate portion 167 similar to those of the low-rigidity disk 142, and has two connecting plate portions 168a of the same shape different from the connecting plate portion 168, and a through hole 163. It has two different through holes 163a of the same shape. In other words, the low-rigidity disk 142a has a low-rigidity portion 171a different from the low-rigidity portion 171 between the inner plate portion 166 and the outer plate portion 167.

The two connecting plate portions 168a have two outer connecting portions 261a arranged on the same straight line passing through the center of the low-rigidity disk 142a, and these outer connecting portions 261a are connected to the outer plate portion 167. ing. The two outer connecting portions 261a are arranged at different phases by 180 degrees in the circumferential direction of the outer plate portion 167, and both protrude from the inner circumferential edge of the outer plate portion 167 inward in the radial direction of the outer plate portion 167. ing.

Furthermore, the two connecting plate portions 168a have two inner connecting portions 262a arranged on the same straight line passing through the center of the low-rigidity disk 142a, and these inner connecting portions 262a connect to the inner plate portion 166. It is connected. The two inner connecting portions 262a are arranged at different phases by 180 degrees in the circumferential direction of the inner plate portion 166, and both protrude outward in the radial direction of the inner plate portion 166 from the outer peripheral edge of the inner plate portion 166. ing. Both of the two outer connecting portions 261a are closer to one of the two inner connecting portions 262a in the circumferential direction of the low-rigidity disk 142a than the other. In other words, each of the two inner connecting portions 262a is closer to one of the two outer connecting portions 261a in the circumferential direction of the low-rigidity disk 142a than the other.

On the one hand, the distance between the outer connecting portion 261a and the inner connecting portion 262a that are far apart in the circumferential direction of the low-rigidity disk 142a is equivalent to the distance between the outer connecting portion 261a and the inner connecting portion 262a that are farthest in the circumferential direction of the low-rigidity disk 142a, on the other hand. It has become.

Further, the two connecting plate portions 168a are provided with two connecting arm portions 263a so as to connect the outer connecting portion 261a and the inner connecting portion 262a which are far apart in the circumferential direction of the low-rigidity disk 142a. That is, the low-rigidity disk 142a is provided with one connecting arm 263a that connects one outer connecting portion 261a and one inner connecting portion 262a that are far apart in the circumferential direction of the low-rigidity disk 142a. The outer connecting portion 261a, the inner connecting portion 262a, and the connecting arm portion 263a constitute one connecting plate portion 168a. Furthermore, the low-rigidity disk 142a is provided with another connecting arm 263a that connects the other outer connecting portion 261a and the other inner connecting portion 262a, which are far apart in the circumferential direction of the low-rigidity disk 142a. The outer connecting portion 261a, the inner connecting portion 262a, and the connecting arm portion 263a constitute the other connecting plate portion 168a.

The two connecting arms 263a extend in an arc shape along the outer circumferential surface of the inner plate portion 166 and the inner circumferential surface of the outer plate portion 167, and are arranged on the same circle concentric with the inner plate portion 166 and the outer plate portion 167. It is located in The two connecting arm portions 263a have the same radial distance from the inner peripheral surface of the outer plate portion 167 and the same radial distance from the outer peripheral surface of the inner plate portion 166.

The low-rigidity disk 142a having such a configuration has two through holes 163a that penetrate in the thickness direction of the low-rigidity disk 142a between the inner plate part 166, the outer plate part 167, and the two connecting plate parts 168a. is formed. The low-rigidity portion 171a having a plurality of connecting plate portions 168a between the inner plate portion 166 and the outer plate portion 167 is formed with a plurality of through holes 163a, so that the low rigidity portion 171a has a plurality of through holes 163a. The rigidity is lower than that of the small diameter disk 141.

[Modification 2]
Moreover, instead of the low-rigidity disk 142, a low-rigidity disk 142b of Modification 2 as shown in FIG. 7 may be used. The low-rigidity disk 142b has an inner plate portion 166 and an outer plate portion 167 similar to those of the low-rigidity disk 142, and has one connection plate portion 168b different from the connection plate portion 168 and two different from the through-holes 163. It has through holes 163b1 and 163b2 at certain locations. In other words, the low-rigidity disk 142b has a low-rigidity portion 171b different from the low-rigidity portion 171 between the inner plate portion 166 and the outer plate portion 167.

The connecting plate portion 168b has one outer connecting portion 261b located on one side of the center in the radial direction of the low-rigidity disk 142b, and this outer connecting portion 261b is connected to the outer plate portion 167. ing. The outer connecting portion 261b projects from the inner peripheral edge of the outer plate portion 167 inward in the radial direction of the outer plate portion 167.

Further, the connecting plate portions 168b are arranged at intervals in the circumferential direction of the low-rigidity disk 142b on the opposite side of the center in the radial direction of the low-rigidity disk 142b, that is, on the opposite side to the outer connecting portion 261b. It has two inner connecting portions 262b, and these inner connecting portions 262b are connected to the inner plate portion 166. The two inner connecting portions 262b are arranged side by side in the circumferential direction of the inner plate portion 166 on the opposite side of the center in the radial direction of the inner plate portion 166, that is, on the opposite side to the outer connecting portion 261b, Both protrude outward in the radial direction of the inner plate part 166 from the outer peripheral edge of the inner plate part 166.

The center of the low-rigidity disk 142b and the outer connecting portion 261b are arranged on a straight line perpendicular to the midpoint of the straight line connecting the two inner connecting portions 262b. The distance between the outer connecting portion 261b and one inner connecting portion 262b is equal to the distance between the outer connecting portion 261b and the other inner connecting portion 262b. This distance is longer than the distance connecting the two inner connecting portions 262b.

Further, the connecting plate portion 168b extends from the side opposite to the outer plate portion 167 of the outer connecting portion 261b to both sides in the circumferential direction of the low-rigidity disk 142b, and connects to the inner connecting portions 262b on both sides. Connecting arm portions 263b are provided at locations. That is, the low-rigidity disk 142b includes one connecting arm 263b that connects the outer connecting portion 261b and one inner connecting portion 262b, and the other connecting arm 263b that connects the outer connecting portion 261b and the other inner connecting portion 262b. An arm portion 263b is provided.

The two connecting arms 263b extend in an arc shape along the outer circumferential surface of the inner plate part 166 and the inner circumferential surface of the outer plate part 167, and extend in the same arc concentric with the inner plate part 166 and the outer plate part 167. placed above. The two connecting arms 263b have the same radial distance from the inner circumferential surface of the outer plate section 167 and the same radial distance from the outer circumferential surface of the inner plate section 166.

In the low-rigidity disk 142b having such a configuration, a through hole 163b1 penetrating in the thickness direction of the low-rigidity disk 142b is formed between the inner plate part 166, the outer plate part 167, and the connecting plate part 168b. . Furthermore, a through hole 163b2 is formed in the low-rigidity disk 142b between the inner plate portion 166 and the connecting plate portion 168b, and penetrates in the thickness direction of the low-rigidity disk 142b. The low-rigidity portion 171b having the connecting plate portion 168b between the inner plate portion 166 and the outer plate portion 167 has a plurality of through holes 163b1 and 163b2 formed therein, so that the low rigidity portion 171b has a connecting plate portion 168b between the inner plate portion 166 and the outer plate portion 167. The rigidity is lower than that of the small-diameter disk 141.

[Modification 3]
Further, instead of the low-rigidity disk 142 described above, a low-rigidity disk 142c of modification 3 as shown in FIG. 8 may be used. The low-rigidity disk 142c has an inner plate portion 166 and an outer plate portion 167 similar to those of the low-rigidity disk 142, and one connecting plate portion 168c different from the connecting plate portion 168 and two different from the through-holes 163. It has through holes 163c1 and 163c2 at different locations. In other words, the low-rigidity disk 142c has a low-rigidity portion 171c, which is different from the low-rigidity portion 171, between the inner plate portion 166 and the outer plate portion 167.

The connecting plate portion 168c is provided at only one location on the low-rigidity disk 142c. The connecting plate portion 168c has one outer connecting portion 261c located on one side of the center in the radial direction of the low-rigidity disk 142c, and this outer connecting portion 261c is connected to the outer plate portion 167. ing. The outer connecting portion 261c projects from the inner circumferential edge of the outer plate portion 167 inward in the radial direction of the outer plate portion 167.

Furthermore, the connecting plate portion 168c has one inner connecting portion 262c located on the opposite side of the center in the radial direction of the low-rigidity disk 142c, that is, on the opposite side to the outer connecting portion 261c. The inner connecting portion 262c is connected to the inner plate portion 166. One inner connecting portion 262c projects from the outer peripheral edge of the inner plate portion 166 to the outside in the radial direction of the inner plate portion 166.

One outer connecting portion 261c and one inner connecting portion 262b have a phase difference of 180 degrees in the circumferential direction of the low-rigidity disk 142c. In other words, a line connecting the outer connecting portion 261c, the center of the low-rigidity disk 142c, and the inner connecting portion 262c forms a straight line.

Further, the connecting plate portion 168c extends from the side opposite to the outer plate portion 167 of the outer connecting portion 261c to both sides in the circumferential direction of the low-rigidity disk 142c, and connects to the connecting arm portions at two locations so as to connect to the inner connecting portion 262c. 263c is provided. That is, the low-rigidity disk 142c has one connecting arm portion 263c that connects the outer connecting portion 261c and the inner connecting portion 262c on one side, and the other connecting arm portion 263c that connects the outer connecting portion 261c and the inner connecting portion 262c on the other side. An arm portion 263c is provided.

The two connecting arms 263c extend in a circular shape along the outer circumferential surface of the inner plate part 166 and the inner circumferential surface of the outer plate part 167, and extend in the same circular shape concentric with the inner plate part 166 and the outer plate part 167. placed above. The two connecting arm portions 263c have the same radial distance from the inner circumferential surface of the outer plate portion 167 and the same radial distance from the outer circumferential surface of the inner plate portion 166.

In the low-rigidity disk 142c having such a configuration, a through hole 163c1 penetrating in the thickness direction of the low-rigidity disk 142c is formed between the outer plate portion 167 and the connecting plate portion 168c. Furthermore, in the low-rigidity disk 142c, a through hole 163c2 is formed between the inner plate portion 166 and the connecting plate portion 168c, and the through-hole 163c2 penetrates in the thickness direction of the low-rigidity disk 142c. The low rigidity portion 171c having the connecting plate portion 168c between the inner plate portion 166 and the outer plate portion 167 has a plurality of through holes 163c1 and 163c2 formed therein, so that the low rigidity portion 171c has a connecting plate portion 168c between the inner plate portion 166 and the outer plate portion 167. The rigidity is lower than that of the small-diameter disk 141.

[Modification 4]
Further, instead of the low-rigidity disk 142 described above, a low-rigidity disk 142d of Modification 4 as shown in FIG. 9 may be used. The low-rigidity disk 142d has an inner plate portion 166 and an outer plate portion 167 similar to those of the low-rigidity disk 142, and has two connecting plate portions 168d of the same shape different from the connecting plate portion 168, and a through hole 163. has two different through holes 163d of the same shape. In other words, the low-rigidity disk 142d has a low-rigidity portion 171d, which is different from the low-rigidity portion 171, between the inner plate portion 166 and the outer plate portion 167.

The two connecting plate portions 168d have two outer connecting portions 261d arranged on the same straight line passing through the center of the low-rigidity disk 142d, and these outer connecting portions 261d are connected to the outer plate portion 167. ing. The two outer connecting portions 261d are arranged at different phases by 180 degrees in the circumferential direction of the outer plate portion 167, and both protrude from the inner circumferential edge of the outer plate portion 167 inward in the radial direction of the outer plate portion 167. ing.

Further, the two connecting plate portions 168d have two inner connecting portions 262d arranged on the same straight line passing through the center of the low-rigidity disk 142d, and these are connected to the inner plate portion 166. . The two inner connecting portions 262d are arranged at different phases by 180 degrees in the circumferential direction of the inner plate portion 166, and both protrude outward in the radial direction of the inner plate portion 166 from the outer peripheral edge of the inner plate portion 166. ing. Both of the two outer connecting portions 261d are closer to one of the two inner connecting portions 262d in the circumferential direction of the low-rigidity disk 142d than the other. In other words, each of the two inner connecting portions 262d is closer to one of the two outer connecting portions 261d in the circumferential direction of the low-rigidity disk 142d than the other.

On the one hand, the distance between the outer connecting portion 261d and the inner connecting portion 262d that are close in the circumferential direction of the low-rigidity disk 142d is equivalent to the distance between the outer connecting portion 261d and the inner connecting portion 262d that are close in the circumferential direction of the low-rigidity disk 142d on the other hand. It has become.

Further, the two connecting plate portions 168d are provided with two connecting arm portions 263d so as to connect the outer connecting portion 261d and the inner connecting portion 262d close to the circumferential direction of the low-rigidity disk 142d. That is, the low-rigidity disk 142d is provided with one connecting arm 263d that connects one outer connecting portion 261d and one inner connecting portion 262d that are close to each other in the circumferential direction of the low-rigidity disk 142d. The outer connecting portion 261d, the inner connecting portion 262d, and the connecting arm portion 263d constitute one connecting plate portion 168d. Further, the low-rigidity disk 142d is provided with another connecting arm 263d that connects the other outer connecting portion 261d and the other inner connecting portion 262d that are close to each other in the circumferential direction of the low-rigidity disk 142d. The outer connecting portion 261d, the inner connecting portion 262d, and the connecting arm portion 263d constitute the other connecting plate portion 168d.

The two connecting arm portions 263d have two outer arcuate portions 301, two folded portions 302, and two inner arcuate portions 303. One connecting arm 263d consists of one outer arcuate portion 301, one folded portion 302, and one inner arcuate portion 303. 301, the other folded part 302, and the other inner arcuate part 303.

One outer arcuate portion 301 extends from one outer connecting portion 261d, beyond one inner connecting portion 262d on the side closer to this, to this side of the other outer connecting portion 261d, and extends from the outer circumferential surface of the inner plate portion 166 and It extends in an arc shape along the inner circumferential surface of the outer plate portion 167. One of the folded parts 302 is folded back toward the inner plate part 166 from the end of the one outer arcuate part 301 on the side opposite to the one outer connecting part 261d. The one inner arcuate portion 303 extends from the end of the one folded portion 302 on the opposite side to the one outer arcuate portion 301 along the outer circumferential surface of the inner plate portion 166 and the inner circumferential surface of the outer plate portion 167. It extends in an arc shape and is connected to one inner connecting portion 262d.

The other outer arcuate portion 301 extends from the other outer connecting portion 261d, beyond the other inner connecting portion 262d on the side closer to this, to the front of the one outer connecting portion 261d, and extends from the outer circumferential surface of the inner plate portion 166 and It extends in an arc shape along the inner circumferential surface of the outer plate portion 167. The other folded portion 302 is folded back toward the inner plate portion 166 from the end of the other outer arcuate portion 301 on the side opposite to the other outer connecting portion 261d. The other inner arcuate portion 303 extends from the opposite end of the other folded portion 302 to the other outer arcuate portion 301 along the outer circumferential surface of the inner plate portion 166 and the inner circumferential surface of the outer plate portion 167. It extends in an arc shape and is connected to the other inner connecting portion 262d.

One outer arcuate portion 301 and the other outer arcuate portion 301 are arranged on a circle concentric with the inner plate portion 166 and the outer plate portion 167, and one inner arcuate portion 303 and the other inner The arcuate portion 303 is arranged on a circle concentric with the inner plate portion 166 and the outer plate portion 167.

The low-rigidity disk 142d having such a configuration has two same-shaped holes that penetrate in the thickness direction of the low-rigidity disk 142d between the inner plate part 166, the outer plate part 167, and the two connecting plate parts 168d. A through hole 163d is formed. The low-rigidity portion 171d having a plurality of connecting plate portions 168d between the inner plate portion 166 and the outer plate portion 167 has a plurality of through holes 163d formed therein, so that the low rigidity portion 171d has a higher rigidity than a disk in which no through holes 163d are formed. It has low rigidity, and has lower rigidity than the small diameter disk 141.

[Modification 5]
Furthermore, instead of the low-rigidity disk 142 described above, a low-rigidity disk 142e of modification 5 as shown in FIG. 10 may be used. The low-rigidity disk 142e has an inner plate portion 166 and an outer plate portion 167 similar to the low-rigidity disk 142, and has one low-rigidity portion 171e different from the connecting plate portion 168. In the low-rigidity disk 142e, a through hole penetrating in the thickness direction is not formed between the inner plate portion 166 and the outer plate portion 167. In other words, the low-rigidity disk 142e has a low-rigidity part 171e different from the low-rigidity part 171 between the inner plate part 166 and the outer plate part 167.

A recess 311 is formed in the low-rigidity disk 142e. The concave portion 311 is recessed from one axial surface in the axial direction of the low-rigidity disk 142e, in other words, in the thickness direction of the low-rigidity disk 142e. The recess 311 has an annular shape that continues all around the circumferential direction of the low-rigidity disk 142e. The recess 311 has a circular shape coaxial with the fitting hole 161 and the outer peripheral edge 162.

By forming the recess 311, the low-rigidity disk 142e is provided with a flat plate-shaped low-rigidity portion 171e that connects the inner plate portion 166 and the outer plate portion 167 in the radial direction of the low-rigidity disk 142e. . The low-rigidity portion 171e between the inner plate portion 166 and the outer plate portion 167 has a thinner axial thickness and lower rigidity than the inner plate portion 166 and the outer plate portion 167 due to the formation of the recess 311. ing. By forming the low-rigidity portion 171e, the low-rigidity disk 142e has lower rigidity than a disk in which the recess 311 is not formed, and has lower rigidity than the small-diameter disk 141.

Here, the low-rigidity disk 142e may be stacked on the small-diameter disk 141 with the concave portion 311 facing the small-diameter disk 141, or may be stacked on the small-diameter disk 141 with the concave portion 311 facing opposite to the small-diameter disk 141. Also good.

Since such a low-rigidity disk 142e has a low rigidity due to the formation of the concave portion 311, the low-rigidity portion 171e can be easily formed. Further, since the recess 311 can be formed in an annular shape, the rigidity of the low-rigidity disk 142e can be reduced uniformly in the circumferential direction. Furthermore, since the recess 311 has an annular shape, stress generated in the low-rigidity disk 142e can be alleviated. Note that the recesses 311 may be formed on both sides of the low-rigidity disk 142e in the axial direction.

In the above embodiment, the expansion side valve mechanism 58 provided on the piston 45 was explained as an example, but it is also possible to have the contraction side valve mechanism 57 provided on the piston 45 have the same structure as the valve mechanism 58. . It is also possible to have the contraction side valve mechanism 65 of the base valve 30 have the same structure as the valve mechanism 58, and the expansion side valve mechanism 66 of the base valve 30 to have the same structure as the valve mechanism 58. It is also possible to

A first aspect of the embodiment described above includes a cylinder in which a working fluid is sealed, a piston that is slidably provided in the cylinder and partitions the inside of the cylinder into two chambers, and a piston that is connected to the piston. The passage is opened between a piston rod extending outside the cylinder, a passage through which working fluid flows out due to movement of the piston, an inner seat, and an inner seat provided outside the inner seat. an outer sheet provided on the outside of the intermediate sheet, an inner peripheral part placed on the inner sheet, an outer peripheral part placed on the intermediate sheet, and an intermediate sheet between the inner peripheral part and the outer peripheral part. a disk-shaped first valve in which a low-rigidity portion is formed; a retainer provided on the opposite side of the inner seat of the first valve; an inner side placed on the retainer and an outer side placed on the outer seat; and a disc-shaped second valve. This makes it possible to increase the damping force in a region where the piston speed is low while suppressing an increase in the damping force in a region where the piston speed is high.

In a second aspect, in the first aspect, the low rigidity portion has a plurality of through holes formed therein.

In a third aspect, in the second aspect, the through hole has an arc shape.

In a fourth aspect, in the first aspect, the low rigidity portion has a recessed portion formed therein.

In a fifth aspect, in any one of the first to fourth aspects, the low rigidity portion is located outside the outer periphery of the inner sheet.

11 Buffer 17 Cylinder 45 Piston 48 1st chamber 49 2nd chamber 51 Piston rod 56 Passage 121 Inner sheet 122 Intermediate sheet 123 Outer sheet 163, 163a, 163b1, 163b2, 163c1, 163c2, 163d Through hole 171, 171a to 171e Low Rigid part 175 Inner peripheral part 176 Outer peripheral part 177 First valve 178 Intermediate part 185 Retainer 205 Second valve 311 Recessed part

Claims (2)

a cylinder in which a working fluid is sealed;
a piston that is slidably provided within the cylinder and partitions the inside of the cylinder into two chambers;
a piston rod connected to the piston and extending outside the cylinder;
a passage through which a working fluid flows due to movement of the piston;
inner sheet,
an intermediate sheet provided outside the inner sheet and having the passageway opened between the intermediate sheet and the inner sheet;
an outer sheet provided outside the intermediate sheet;
a disk-shaped first valve having an inner circumferential portion placed on the inner seat, an outer circumferential portion placed on the intermediate seat, and a low-rigidity portion formed in an intermediate portion between the inner circumferential portion and the outer circumferential portion;
a retainer provided on a side opposite to the inner seat of the first valve;
a disk-shaped second valve whose inner side is placed on the retainer and whose outer side is placed on the outer seat;
has
The low-rigidity portion is a shock absorber in which a recess is formed . The shock absorber according to claim 1 , wherein the low-rigidity portion is located outside an outer periphery of the inner sheet.

Images