JP5057394B2 - Rotary valve - Google Patents

Description

The present invention relates to an improvement of a rotary valve.

  Conventionally, in this type of rotary valve, a hollow hole is provided in the piston rod of the shock absorber to form a housing, and a cylindrical valve body is rotatably inserted into the housing. A pair of ports that communicate with the inside and outside of the housing and face each other are formed, and a pair of orifice holes that communicate with the inside and outside of the valve body and face each other so as to face each other and face the ports of the housing are formed. What is provided is known.

In this conventional rotary valve, by rotating the valve body with respect to the housing, the degree of overlap (wrap) between the port and the orifice hole is changed to change the flow passage area, and the hydraulic oil is transferred to the rotary valve. It is possible to change the pressure loss when passing through the valve, and to adjust the damping force generated by the shock absorber.
JP 2008-39065 A (FIG. 1)

  Specifically, the rotary valve described above is provided in the middle of a bypass passage that bypasses the main damping passage provided on the piston of the shock absorber and is opened and closed by the leaf valve, and communicates the upper chamber and the lower chamber. In addition to a pair of orifice holes, two pairs of second orifice holes are juxtaposed in the bypass passage in order to adjust the damping characteristics (characteristics of the generated damping force with respect to piston speed) over a wide range from soft to hard. .

  This bypass path is branched from an orifice hole and a second orifice hole provided in the middle from the lower chamber to the upper chamber, and the bypass path branched by the second orifice hole is a partition provided on the outer periphery of the piston rod. A chamber formed by the member and a passage provided in the partition member are formed and communicated with the upper chamber, and the passage is opened and closed by a leaf valve. The bypass path branched by the orifice hole is formed by a sub-passage that is provided in the piston and bypasses the main damping passage, and communicates with the upper chamber.

  When the damping force is soft, the orifice area is made to face the port to increase the flow area, but the bypass path leading to the orifice hole leads to the second orifice hole restricted by the leaf valve. Since no resistance element is provided for the bypass passage, when the damping force is softened, the flow rate of the hydraulic oil passing through the orifice hole becomes very large.

  Here, the valve body of the rotary valve is cylindrical as described above, and two orifice holes are provided to allow passage of a large flow rate, and these orifice holes face each other and face each other. Therefore, when the flow of hydraulic oil collides from the front in the valve body, especially when the flow rate passing through the orifice hole increases, vortices are generated in the valve body or aeration is generated, causing abnormal noise. There is.

  Accordingly, the present invention has been developed to improve the above-described problems, and an object of the present invention is to provide a rotary valve capable of suppressing the generation of abnormal noise.

In order to achieve the above object, the means of the present invention includes a cylinder, a piston rod movably inserted into the cylinder, a slidably inserted into the cylinder and mounted on the outer periphery of the piston rod. A piston having a main damping passage that divides the upper chamber and the lower chamber and communicates the upper chamber and the lower chamber; and a bypass passage that bypasses the main damping passage and communicates the upper chamber and the lower chamber. The bypass passage is formed by a hollow hole that opens from the tip of the piston rod and communicates with the lower chamber, and a partition member that is mounted on the outer periphery of the piston rod and on the upper chamber side from the piston, and is formed on the partition member. that the room is communicated to the upper chamber by a passage, the auxiliary passage provided in the spacer which is interposed between the partition member and the piston, et al provided in the piston rod along the same circumference A hollow hole and a sub passage and a pair of first port communicating with, the piston rod is provided along the same circumference formed by the second port communicating the hollow bore and the room, into the hollow bore Te A cylindrical valve body is accommodated so as to be rotatable in the circumferential direction, and the valve body is provided with a pair of first orifice holes facing each first port and a second orifice hole capable of facing the second port, In the rotary valve in the shock absorber that rotates the valve body to communicate the orifice hole corresponding to each port to change the flow area, one first port, the other first port, and the one first orifice hole, The shock absorber is characterized in that each port and each orifice hole are arranged so that the axis of the other first orifice hole does not coincide and the extension line does not intersect .

According to the rotary valve of the present invention, the axis of each port in the pair of first ports is not matched, and the axis of each orifice hole in the pair of first orifice holes corresponding to these ports is similarly arranged not to match. Therefore, it is avoided that the flow of the working fluid collides from the front in the valve body. Therefore, even if the flow rate of the working fluid passing through each orifice hole is increased, vortex is generated or aeration is generated in the valve body. The generation of abnormal noise can be suppressed.
Moreover, since the extension lines of the axis lines of the respective ports in the pair of first ports do not intersect, the extension lines of the axis lines of the respective orifice holes in the pair of first orifice holes corresponding to these ports do not intersect. The collision of the two working fluid flows introduced into the valve body can be avoided, and the generation of abnormal noise can be further suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partially enlarged longitudinal sectional view of a shock absorber to which a rotary valve according to a reference example is applied, and FIG. 2 is a sectional view of the rotary valve.
FIG. 3 is a sectional view of a rotary valve according to one embodiment of the invention of each claim, and the basic structure of a shock absorber to which this rotary valve is applied is the same as that of FIG.
Before describing the rotary valve of FIG. 3, the basic structure of the shock absorber will be described with reference to FIGS.

As shown in FIG. 1, the rotary valve 5 according to the reference example is applied to a shock absorber D and used for adjusting a damping force. In this case, in detail, the housing is a piston rod 2 and the piston rod 2 is surrounded by the periphery. A cylindrical valve body 8 is rotatably housed in the direction.

  On the other hand, a shock absorber D to which the rotary valve of the present invention is applied includes a cylinder 1, a piston rod 2 that is slidably inserted into the cylinder 1, and a piston rod 2 that is slidably inserted into the cylinder 1. A piston 3 having main damping passages 3a and 3b that divide the inside of the cylinder 1 into an upper chamber R1 and a lower chamber R2 and communicate the upper chamber R1 and the lower chamber R2, and a main damping passage 3a, A bypass passage 4 that bypasses 3b and communicates the upper chamber R1 and the lower chamber R2, and a rotary valve 5 that is provided in the middle of the bypass passage 4 and changes the flow passage area of the bypass passage 4, A working fluid such as hydraulic oil is sealed in the cylinder 1. In the shock absorber D, the damping force is adjusted by changing the flow passage area in the bypass passage 4 by the rotary valve 5 described above.

  Although not shown, the upper and lower ends of the cylinder 1 in FIG. 1 are sealed with a sealing member (not shown), and the cylinder 1 is held in a sealed state. When the working fluid is a liquid, when the shock absorber D expands or contracts, the piston rod 2 enters or leaves the cylinder 1 to compensate for the amount of liquid that becomes excessive or insufficient in the cylinder 1. Therefore, although not shown, it is natural that a gas chamber defined by a free piston inserted below the cylinder 1 or a reservoir communicating with the cylinder 1 is provided.

  Hereinafter, each member will be described in detail. The cylinder 1 is formed in a cylindrical shape, and a rod guide (not shown) for slidably supporting the piston rod 2 is provided at the upper end in FIG. .

  The piston rod 2 includes a hollow hole 2a that opens from the lower end in FIG. 1 and faces the lower chamber R2, and a control rod insertion hole 2b that continues to the hollow hole 2a and communicates with an upper end (not shown). A spacer 6 and a partition member 7 are attached to the outer periphery of the piston 3 and an upper chamber R1 side above the piston 3 in FIG.

  A cylindrical valve body 8 of the rotary valve 5 is rotatably accommodated in the hollow hole 2a of the piston rod 2.

The lower side of the piston rod 2 is set to a small diameter to form a small diameter portion 2c and a stepped portion 2d. The small diameter portion 2c has a pair of first ports 2g communicating the hollow hole 2a to the outside of the piston rod. , 2h, and two ports 2e, upper and lower, which communicate with the outside of the piston rod separately from the ports 2g and 2h, and are arranged at an interval of 180 degrees in the circumferential direction and face each other. 2f is opened.

As shown in FIGS. 1 and 2, these ports 2g and 2h are both disposed on the same circumference of the piston rod 2 functioning as a housing, and the axes a and b of one port 2g and the other port 2h. Does not match. In the case of this reference example , the other port 2h is not arranged in the range W projected from the one port 2g along the axis a of the one port 2g onto the opposite surface of the small diameter portion 2c of the piston rod 2. The ports 2g and 2h do not face each other in the axial direction. As shown in the figure, the ports 2g and 2h are installed with an interval of 90 degrees in the circumferential direction.

In the case of this reference example , the second ports 2e and 2f and the ports 2g and 2h described above are circular holes, but the shape is not limited to this.

  The piston 3 is formed in an annular shape, and when the shock absorber D extends through the upper chamber R1 and the lower chamber R2, the working fluid passes and the main damping passage 3a on the expansion side, the upper chamber R1 and the lower chamber R2 are passed. And a pressure-side main damping passage 3b through which the working fluid passes when the shock absorber D is compressed. The leaf valves V1 and V2 are stacked on the upper and lower sides of the piston 3, respectively, and the lower end serving as the outlet end of the main damping passage 3a is opened and closed by the leaf valve V1, and conversely, the outlet end of the main damping passage 3b. The upper end is opened and closed by a leaf valve V2.

  Therefore, when the shock absorber D is extended, the leaf valve V1 applies a resistance to the flow of the working fluid that passes through the main damping passage 3a on the expansion side and moves from the upper chamber R1 to the lower chamber R2, thereby shock absorber. The other leaf valve V2 generates an extension-side damping force in D, and when the shock absorber D is compressed, the working fluid moves from the lower chamber R2 to the upper chamber R1 through the compression-side main damping passage 3b. A resistance is applied to the flow of the pressure to generate a compression side damping force in the shock absorber D.

  The spacer 6 is formed in a bottomed cylindrical shape, and a hole 6a that allows insertion of the small-diameter portion 2c of the piston rod 2 is provided at the bottom, and a notch 6c that communicates inside and outside is provided in the cylindrical portion 6b. The rod 2 is assembled on the outer periphery of the small diameter portion 2c. In addition, the notch 6c may be provided in the edge part of the cylinder part 6b, and may be provided in the middle of the cylinder part 6b in the shape of a hole. In this embodiment, the spacer 6 is directly stacked on the leaf valve V2 stacked above the piston 3, and functions as a valve stopper that regulates the amount of deflection of the leaf valve V2. Also good.

  The partition member 7 includes an annular valve disk 9 assembled to the outer periphery of the small diameter portion 2c of the piston rod 2, and a bottomed cylindrical cap 10 assembled to the outer periphery of the valve disk 9 and the piston rod 3. The valve disk 9 and the cap 10 partition the room 11 in the upper chamber R1.

  Specifically, the valve disk 9 includes an extension side passage 9a that penetrates the valve disk 9 and a pressure side passage 9b.

  The outlet end of the extension side passage 9a is opened and closed by a leaf valve V3 stacked below the valve disk 9 in FIG. 1, and the extension side passage 9a is a one-way passage that is opened only during the extension stroke of the shock absorber D. The resistance is set by the leaf valve V3 to the set working fluid. On the other hand, the outlet end of the pressure side passage 9b is opened and closed by a leaf valve V4 stacked above the valve disc 9 in FIG. 1, and the pressure side passage 9b is set as a one-way passage that is opened only during the compression stroke of the shock absorber D. The leaf valve V4 provides resistance to the working fluid passing therethrough. Since the bending rigidity of the leaf valves V3 and V4 is set to be smaller than the bending rigidity of the leaf valves V1 and V2 stacked on the piston 3, the valve opening pressure is lower than the valve opening pressure of the leaf valves V1 and V2. The expansion side passage 9a and the pressure side passage 9b are opened by the pressure.

  The cap 10 is formed in a bottomed cylindrical shape, and a hole 10a that allows the small-diameter portion 2c of the piston rod 2 to be inserted is provided at the bottom, and the opening of the cylindrical portion is fitted to the outer periphery of the valve disc 9. Are combined. And between the bottom part of this cap 10 and the valve disc 9, the valve | bulb restraint 12 which is a bottomed cylinder shape and is set to a diameter smaller than the cap 10 is interposed, The said valve | bulb restraint 12 is the bottom part. The leaf valve V3 is set to open outward by preventing the leaf valve V3 from lifting from the inner periphery of the valve disc 9. Further, the valve restraint 12 includes a notch 12b in the cylindrical portion 12a, and the inside and the outside communicate with each other by the notch 12b. In addition, the notch 12b may be provided in the edge part of the cylinder part 12a, and may be provided in the middle of the cylinder part 12a in the shape of a hole.

  Further, the small diameter portion 2c of the piston rod 2 includes, in order from the top in FIG. 1, a valve stopper 13, a leaf valve V4, a valve that is restricted from moving upward with respect to the piston rod 2 by the step portion 2d of the piston rod 2. The disc 9, the leaf valve V 3, the valve restraint 12, the cap 10, the spacer 6, the leaf valve V 2, the piston 3, the leaf valve V 1, and the annular valve stopper 14 for regulating the leaf valve V 1 are assembled. Each member described above is fixed to the piston rod 2 by a piston nut 15 screwed to the lowermost end of the piston rod 2.

  Thus, in a state where each member is assembled and fixed to the piston rod 2, the ports 2 g and 2 h provided on the piston rod 2 face the cylindrical portion 6 b of the spacer 6, and further, the cylindrical portion 12 a of the valve retainer 12. The second ports 2e and 2f provided on the piston rod 2 face each other, and the hollow hole 2a facing the lower chamber R2 is connected to the upper chamber R1 via the ports 2g and 2h and the notch 6c provided on the spacer 6. The second port 2e, 2f, the notch 12b provided in the valve retainer 12, the chamber 11 partitioned by the valve disc 9 and the cap 10, and the extension side passage 9a and the pressure side passage 9b provided in the valve disc 9. Via the upper chamber R1.

Therefore, in this reference example , the bypass path 4 includes the hollow hole 2a that opens from the tip of the piston rod 2 and communicates with the lower chamber R2, the ports 2g and 2h, the notches 6c provided in the spacer 6, and the second ports 2e and 2f. In this case, the notch 12b provided in the valve holding member 12, the chamber 11, the extension side passage 9a and the pressure side passage 9b are configured. In this case, the passage formed in the partition member 7 is the extension side passage provided in the valve disc 9. 9 a and the pressure side passage 9 b, and the sub passage is formed by a notch 6 c provided in the spacer 6.

  The extension side passage 9a and the pressure side passage 9b functioning as passages provided in the partition member 7 are set to be one-way, and are opened and closed by the leaf valves V3, V4. Therefore, the leaf valves V3, V4 are opened. The corresponding extension side passage 9a and pressure side passage 9b are closed until the pressure is reached, and the bypass passage 4 is connected to the upper chamber R1 and the lower chamber via the hollow hole 2a, the ports 2g, 2h, and the notch 6c provided in the spacer 6. R2 is communicated.

  Subsequently, the cylindrical valve body 8 in the rotary valve 5 accommodated in the hollow hole 2a of the piston rod 2 has its outer peripheral surface in sliding contact with the inner peripheral surface of the hollow hole 2a, and can be rotated in the circumferential direction. The upper end of the piston rod 2 is connected to the control rod 16 inserted into the control rod insertion hole 2b.

  The control rod 16 is connected to an output shaft of a stepping motor (not shown) fixed to the upper end of the piston rod 2, and the valve body 8 is moved in the circumferential direction with respect to the piston rod 2 by driving the stepping motor. Step rotation can be performed for each predetermined rotation angle.

  Further, a cylindrical stopper 18 is press-fitted in the hollow hole 2a of the piston rod 2 and below the valve body 8 in FIG. 1, and this stopper 18 prevents the valve body 8 from falling off the piston rod 2. is doing. Further, a cylindrical resin bearing 17 is interposed between the stopper 18 and the valve body 8 to ensure smooth rotation of the valve body 8.

The valve body 8 includes two pairs of upper and lower second orifice holes 19 and 20 that communicate with the inside and outside of the side portion and face the second ports 2e and 2f formed in the small diameter portion 2c of the piston rod 2, and the valve body 8. And a pair of first orifice holes 21 and 22 that can be opposed to the first ports 2g and 2h, respectively.

  As shown in FIGS. 1 and 2, each of the second orifice holes 19 and 20 includes circular holes 19a and 20a and slits 19b and 20b communicated with the circular holes 19a and 20a along the circumferential direction, respectively. And the slits 19b and 20b themselves pass through the thickness of the valve body 8 and communicate with the inside and outside of the valve body 8, and the paired circular holes 19a and 20a are 180 degrees in the circumferential direction. Are arranged so as to face each other and face each other.

  As shown in FIGS. 1 and 2, the orifice holes 21 and 22 are both circular holes, arranged on the same circumference of the valve body 8, and one orifice hole 21 and the other orifice hole 22. The axes a and b are not matched. As described above, the axis a of one orifice hole 21 and the axis b of the other orifice hole 22 do not have to coincide with each other. In this embodiment, one orifice hole 21 is replaced with one orifice hole 21. The other orifice hole 22 is not arranged in the range X projected on the opposite surface of the valve body 8 along the axis a, so that these orifice holes 21 and 22 do not face each other in the axial direction. It has become. In FIG. 2, each orifice hole 21, 22 is completely opposed to the corresponding port 2 g, 2 h, the axis of one orifice hole 21 and the axis of one port 2 g coincide, and the other orifice hole 22 2 and the axis of the other port 2h coincide with each other, FIG. 2 shows two axes a and b.

  As shown in the figure, the orifice hole 21 and the orifice hole 22 are installed at an interval of 90 degrees in the circumferential direction like the ports 2g and 2h.

  Further, when one orifice hole 21 is completely opposed to the corresponding one port 2g, the other orifice hole 22 is directly opposed to the corresponding other port 2h. It is designed to be maintained in a state.

  In the valve body 8 configured as described above, when the orifice holes 21 and 22 are opposed to the corresponding ports 2g and 2h, the notch 6c, which is a sub-passage, can be communicated with the hollow hole 2a. As a result, the upper chamber R1 and the lower chamber R2 can be in communication with each other. Further, when the ports 2g and 2h are closed with the side surfaces of the valve body 8 facing the ports 2g and 2h without the orifice holes 21 and 22 facing the ports 2g and 2h, the communication between the upper chamber R1 and the lower chamber R2 is established. Further, the flow area of the flow path formed by the ports 2g, 2h and the orifice holes 21, 22 is changed by changing the degree of overlap between the ports 2g, 2h and the orifice holes 21, 22. It can be changed.

  Similarly, the second orifice holes 19 and 20 are opposed to the corresponding second ports 2e and 2f, respectively, so that the chamber 11 communicates with the inside of the valve body 8, and the leaf valve V3 stacked on the valve disk 9 is stacked. When one of V4 is opened, the upper chamber R1 and the lower chamber R2 are brought into communication with each other, and the side surface of the valve body 8 is made to face the second port 2e, without the second orifice holes 19 and 20 facing the second ports 2e and 2f. When the second ports 2e and 2f are closed so as to face 2f, the communication between the upper chamber R1 and the lower chamber R2 through the space 11 is blocked, and the second ports 2e and 2f By changing the overlapping degree of the second orifice holes 19 and 20, the flow area in the flow path formed by the second ports 2e and 2f and the second orifice holes 19 and 20 can be changed. Going on.

  Further, since the second orifice holes 19 and 20 include not only the circular holes 19a and 20a having a longer width in the circumferential direction than the orifice holes 21 and 22, but also the slits 19b and 20b, the orifice holes 21 and 22 are respectively connected to the ports. When the valve element 8 is rotated in the circumferential direction so that the slits 19b and 20b of the second orifice holes 19 and 20 are opposed to the second ports 2e and 2f from the state of facing the 2g and 2h, the second orifice Before the holes 19 and 20 cannot face the second ports 2e and 2f, the orifice holes 21 and 22 cannot face the ports 2g and 2h, and the ports 2g and 2h are closed. When the orifice holes 21 and 22 face the ports 2g and 2h, that is, when the orifice holes 21 and 22 face the ports 2g and 2h completely, the second orifice holes 19 and 20 are circular. The holes 19a and 20a are also directly opposed to the second ports 2e and 2f, so that the flow passage area of the bypass passage 4 is maximized, and the valve body 8 is connected to the slits 19b and 20b of the second orifice holes 19 and 20 to the second ports 2e and 2f. When it is rotated in the circumferential direction so as to be opposed to each other, the flow passage area in the bypass passage 4 is gradually reduced. Finally, not only the ports 2g and 2h but also the second ports 2e and 2f As a result, the bypass passage 4 is closed because the flow passage area is zero.

  As described above, the rotary valve 5 is configured by the above-described valve body 8 and the piston rod 2 that functions as a housing with the hollow hole 2a that accommodates the valve body 8. By rotating the valve body 8, the flow passage area in the bypass passage 4 can be changed.

  When the shock absorber D expands and contracts, when the orifice holes 21 and 22 and the ports 2g and 2h are in direct communication with each other, the working fluid is opened and closed by the leaf valves V1 and V2. Prior to the main damping passages 3a and 3b, the upper chamber R1 and the lower chamber R2 pass back and forth through the orifice holes 21 and 22 and the ports 2g and 2h. At this time, the second orifice holes 19 and 20 are opposed to the second ports 2e and 2f, but when the expansion / contraction speed of the shock absorber D is in the low speed region, the pressure in the upper chamber R1 or the lower chamber R2 is changed to the leaf valve V3. , V4 does not reach the valve opening pressure, the expansion side passage 9a and the compression side passage 9b remain closed, and the expansion / contraction speed of the shock absorber D is in the middle / high speed range, and the pressure in the upper chamber R1 or the lower chamber R2 is Even if the opening pressure of the valves V3 and V4 is reached and the expansion side passage 9a or the pressure side passage 9b is opened, since the resistance in the leaf valves V3 and V4 is large, the working fluid is preferentially connected to the orifice holes 21 and 22 and the ports. Passes 2g and 2h and moves back and forth between the upper chamber R1 and the lower chamber R2.

  When the orifice holes 21 and 22 and the ports 2g and 2h are in communication with each other, the flow passage area of the bypass passage 4 is large and the flow passage resistance is small. The shock absorber D generates a soft damping force.

  As described above, when the orifice holes 21 and 22 and the ports 2g and 2h are in communication with each other, the area of the flow path formed by the orifice holes 21 and 22 and the ports 2g and 2h is large, and the amount of passing working fluid is large. Become more. When the shock absorber D is extended and the working fluid moves from the upper chamber R1 to the lower chamber R2, the working fluid has a large flow rate from the ports 2g and 2h to the orifice holes 21 and 22 and the valve body 8. However, the two flows of the working fluid that have entered the valve body 8 through the orifice holes 21 and 22 are not arranged on the same axis even if the ports 2g and 2h are on the same circumference. Similarly, the orifice holes 21 and 22 corresponding to the ports 2g and 2h are not arranged on the same axis even if they are on the same circumference, so that they do not collide from the front in front of those intersecting in the valve body 8, The flow of the working fluid introduced into the valve body 8 from the orifice holes 21 and 22 is directed to the lower side of the valve body 8 in FIG. 1, avoiding a collision from the front, and finally in the lower chamber R2. Will be reached.

  Therefore, in the rotary valve 5, the axes a and b of the ports 2g and 2h are not matched, and the axes a and b of the orifice holes 21 and 22 corresponding to the ports 2g and 2h are not matched as well. Since the flow of the working fluid is prevented from colliding from the front in the valve body 8 even if the flow rate of the working fluid passing through the orifice holes 21 and 22 increases, the valve body No vortex or aeration is generated in 8, and the generation of abnormal noise can be suppressed.

As described above, the axes a and b of the ports 2g and 2h are not matched, and the axes a and b of the orifice holes 21 and 22 corresponding to the ports 2g and 2h are similarly arranged so as not to match. In this reference example , in addition to the fact that the axes a and b of the ports 2g and 2h do not coincide with the axes a and b of the orifice holes 21 and 22, The other port 2h is not disposed in the range W projected on the opposite surface of the piston rod 2 which is the housing along the axis a of the port 2g, and one orifice hole 21 is set to the axis b of the orifice hole 21. Since the other orifice 21 is not disposed in the range X projected onto the opposite surface of the valve body 8 along the other port 2, the flow of the working fluid passing through the one port 2 g and the orifice hole 21 and the other port 2. And it prevents the flow of the working fluid passing through the orifice 22 will vigorously collide, further it is possible to suppress the abnormal noise.

In the rotary valve 5 according to the illustrated reference example, although the axes a and b of the ports 2g and 2h do not coincide with each other, the ports 2g and 2h are opened in a direction toward the center of the piston rod 2. These axis lines a and b intersect at the center of the piston rod 2, and each of the orifice holes 21 and 22 corresponding to the ports 2g and 2h is also the center of the valve element 8 although the axis lines a and b do not coincide with each other. Therefore, the flow of the working fluid passing through one port 2g and the orifice hole 21 and the flow of the working fluid passing through the other port 2h and the orifice hole 22 intersect.
However, in the rotary valve 5 according to the embodiment shown in FIG. 3 , the other port 2h is disposed in a range W in which one port 2g is projected onto the opposite surface of the piston rod 2 as a housing along the axis a of the port 2g. In addition, the axes of the pair of ports 2g, 2h do not coincide with each other, and the extension lines do not intersect with each other, and the axes of the pair of orifice holes 21, 22 corresponding to these ports 2g, 2h do not coincide with each other. The extension lines are arranged so that they do not intersect.
Therefore, it is possible to avoid the collision of the flow of the two working fluids introduced into the valve body 8, and it is possible to further suppress the generation of abnormal noise. Even if the other port 2h is arranged in a range W where one port 2g is projected onto the opposite surface of the piston rod 2 as a housing along the axis a of the port 2g, the axes a and b of the port 2g and the port 2h Even if the other port 2h is arranged in the range X in which one orifice hole 21 is projected onto the opposite surface of the valve body 8 along the axis b of the orifice hole 21, the orifice hole 21 and the orifice If the axes a and b of the hole 22 do not coincide with each other, the generation of abnormal noise can be suppressed.

  Subsequently, when the valve body 8 is rotated from the above state to reduce the lap area between the orifice holes 21 and 22 and the ports 2g and 2h, the working fluid becomes the orifice holes 21 and 22 and the ports 2g and 2h. Since the resistance at the time of passing through the valve is increased and it is difficult to pass through the valve, the bending rigidity of the leaf valves V3 and V4 is set to be smaller than the bending rigidity of the leaf valves V1 and V2. Is opened to move back and forth between the upper chamber R1 and the lower chamber R2 through the second orifice holes 19 and 20. The damping force can be adjusted by changing the lap area of the second orifice holes 19 and 20 and the second ports 2e and 2f. Further, when the expansion / contraction speed of the shock absorber increases, the piston 2 is finally laminated. The leaf valves V1 and V2 thus opened are opened. Also in this case, since the working fluid in the upper chamber R1 and the lower chamber R2 exchanges with each other through the second orifice holes 19 and 20, the lap area between the second orifice holes 19 and 20 and the second ports 2e and 2f is reduced. The damping force can be adjusted by changing, and the smaller the wrap area between the second orifice holes 19 and 20 and the second ports 2e and 2f, the smaller the flow path area, and the main damping passage 3a, The flow resistance in the bypass 4 that bypasses 3b increases, the damping coefficient in the shock absorber D increases, and the shock absorber D generates a hard damping force.

  Since the auxiliary passage in the bypass passage 4 of the shock absorber D is formed in the spacer 6 interposed between the partition member 7 and the piston 3 as described above, the valve body 8 in the rotary valve 5 is conventionally used. Compared with this rotary valve, at least the thickness of the leaf valve V2 and the valve stopper can be shortened in the axial direction, which reduces the manufacturing cost and is economically advantageous.

  The presence / absence and shape of the second orifice holes 19 and 20 and the second ports 2e and 2f are arbitrary, and the shapes of the orifice holes 21 and 22 and ports 2g and 2h are also arbitrary. It can be set to a suitable shape according to the attenuation characteristic.

 Although the description of the embodiment of the rotary valve is finished as described above, it is needless to say that the rotary valve of the present invention can be applied to other parts of the shock absorber without using the piston rod as a housing. . Also, the scope of the invention is not limited to the details shown or described.

It is a partially expanded longitudinal cross-sectional view of the buffer to which the rotary valve concerning a reference example was applied. It is a cross-sectional view of a rotary valve in FIG. It is sectional drawing of the rotary valve concerning one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston rod 2a Hollow hole 2b in piston rod Control rod insertion hole 2c in piston rod Small diameter part 2d in piston rod Step part 2e, 2f in piston rod Second port 2g in piston rod, port 2 in piston rod 3 Piston 3a 3b Main damping passage 4 Bypass passage 5 Rotary valve 6 Spacer 6a Spacer 6b Spacer cylinder 6c Spacer notch 7 Partition member 8 Valve body 9 in rotary valve Valve disc 9a Extension side passage 9b Pressure side passage 10 Cap 10a Hole in cap 11 Chamber 12 Valve restraint 12a Tube portion 12b in valve restraint Notches 13, 14 in valve restraint Valve stopper 15 Piston nut 16 Control rod 17 Alling 18 Stopper 19, 20 Second orifice hole 19a, 20a Circular hole 19b, 20b Slit 21, 22 Orifice hole a, b Axis D Buffer R1 Upper chamber R2 Lower chamber V1, V2, V3, V4 Leaf valve W One port Is a range in which one orifice hole is projected on the opposite surface of the valve body along the axis of one orifice hole.

Claims (3)

A cylinder, a piston rod that is slidably inserted into the cylinder, and is slidably inserted into the cylinder and mounted on the outer periphery of the piston rod to divide the inside of the cylinder into an upper chamber and a lower chamber; A piston having a main damping passage that communicates with the chamber, and a bypass passage that bypasses the main damping passage and communicates the upper chamber and the lower chamber. The bypass passage is opened downward from the tip of the piston rod. A chamber that is formed by a hollow hole that communicates with the chamber, a partition member that is an outer periphery of the piston rod and is mounted on the upper chamber side from the piston, and that communicates with the upper chamber by a passage formed in the partition member; sub-passage and a pair of first ports communicating the hollow bore and the auxiliary passage provided in the piston rod along the same circumference which is provided in the spacer interposed between the piston Housing and bets, the piston rod is provided along the same circumference formed by the second port communicating the hollow bore and the room, into the hollow hole circumferentially rotatably tubular valve body The valve body is provided with a pair of first orifice holes opposed to each first port and a second orifice hole capable of facing the second port, and the valve body is rotated so as to correspond to each port. In the rotary valve in the shock absorber that changes the flow passage area by communicating with each other, the axis of one first port and the other first port and the axis of one first orifice hole and the other first orifice hole do not coincide with each other. A rotary valve in a shock absorber, wherein each port and each orifice hole are arranged so that the extension lines do not cross each other.   In the pair of first ports and the pair of first orifices, the other port is not arranged in a range projected on the opposite surface of the piston rod along the axis of one port, and one orifice hole is replaced with the axis of one orifice hole. 2. The rotary valve in the shock absorber according to claim 1, wherein the other orifice hole is not disposed in a range projected on the opposite surface of the valve body along the axis. The rotary valve in the shock absorber according to claim 1 or 2, wherein the spacer is formed in a bottomed cylindrical shape, and a sub-passage including a notch or a hole is formed in the cylindrical portion.

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