JP4740195B2 - Hydraulic shock absorber - Google Patents

Description

  The present invention relates to a hydraulic shock absorber, and more particularly, to an improvement in a hydraulic shock absorber that is formed in, for example, a cylindrical shape and can adjust the generated damping force depending on the expansion / contraction position.

  For example, there have been various proposals for a hydraulic shock absorber formed in a cylindrical shape and capable of adjusting the level of generated damping force depending on the expansion / contraction position. Discloses a damping force that is adjustable depending on a sliding position of a piston body in a cylinder body forming a hydraulic shock absorber.

  That is, Patent Document 1 discloses a damping valve in which two pressure chambers that are defined by a piston body and sandwich the piston body when the piston body slides in the cylinder body are arranged in the piston body. In this case, a hydraulic shock absorber is disclosed in which a predetermined damping force is generated by a damping valve at this time.

  And in this patent document 1, it is in said hydraulic shock absorber, Comprising: A cylinder body shall have a pair of groove | channel along the axial direction of a cylinder body in the inner periphery of both ends, Therefore, piston in a cylinder body When the body reaches a state near the stroke end and faces the groove, a bypass path is formed that bypasses the piston body, that is, bypasses the damping valve disposed on the piston body. It is disclosed that the pressure chamber is in a state of communicating through this bypass passage.

  In addition, the above-mentioned Patent Document 1 includes a pair of check valves in the above-described hydraulic shock absorber that prevent the piston body from flowing in opposite directions. When the pressure chamber communicates via the bypass passage, the bypass passage is maintained in the communication state when the piston body slides in one selected direction within the cylinder body. Discloses that the bypass path can be cut off.

  Therefore, according to the hydraulic shock absorber disclosed in Patent Document 1, when the piston body slides near the center of the cylinder body, both pressure chambers are connected via the damping valve disposed on the piston body. In other words, a state of generation of a high damping force can be realized.

  On the other hand, when the piston body slides in the cylinder body with a large stroke and exceeds the so-called predetermined stroke range, the bypass passage is opened and both pressure chambers are communicated with each other through the bypass passage. Thus, it is possible to embody a state in which the damping force that has been high until then is lowered.

When the piston body that has been slid in the cylinder body to the vicinity of the stroke end is reversed and returned to the vicinity of the center of the cylinder body, the bypass path that has been in communication until then is blocked. Therefore, it is possible to embody the state of occurrence of a high damping force in the compression side operation.
JP 2003-322193 A (see paragraphs 0021, 0024 to 0026, 0028 to 0030, and FIGS. 1 and 3 in the specification)

  However, in the hydraulic shock absorber disclosed in Patent Document 1 described above, there is no particular problem in terms of the basic point of view that the height of the generated damping force can be adjusted depending on the expansion / contraction position. Considering the implementation, it may be pointed out that there is a minor defect.

  That is, including the above-described hydraulic shock absorber, in the case of a hydraulic shock absorber that is of the kind of position-dependent type, the piston body is positioned in a so-called neutral position in the cylinder body when installed. It is important to be.

  However, considering the fact that this type of hydraulic shock absorber is installed, the mounting length of the hydraulic shock absorber is often divided due to various factors. Therefore, it is not easy to make the piston body in a neutral position with respect to the cylinder body, especially in a large-sized hydraulic shock absorber, and there is a concern that an accurate installation state cannot be realized from this. There is.

  If the piston body is installed without being in a neutral position with respect to the cylinder body, the timing at which the bypass path formed by the piston body and the groove of the cylinder body is opened and closed will be out of order. It may be pointed out that the meaning of installing the hydraulic shock absorber is wasted because it becomes impossible to expect the predetermined function.

  On the other hand, in the hydraulic shock absorber described above, the bypass path is formed by a piston body and a groove provided on the inner periphery of the cylinder body. At this time, between the piston body and the cylinder body, It is known that a sliding gap basically appears from the viewpoint of ensuring the slidability between the two, and therefore it is well known that hydraulic fluid leaks through this sliding gap.

  That is, if a seal member such as a piston seal is provided on the outer periphery of the piston body in order to prevent leakage of hydraulic oil between the piston body and the cylinder body, a groove that forms a bypass path of the seal member Since the so-called protrusion of the piston body is manifested, the slidability of the piston body with respect to the cylinder body, that is, the operability of the hydraulic shock absorber is hindered, so that leakage prevention by the seal member cannot be practiced.

  Based on this, regardless of whether the hydraulic fluid leakage due to the above-mentioned sliding gap is not a problem, depending on the size and application of the hydraulic shock absorber, the hydraulic oil leakage due to this sliding clearance may cause the hydraulic shock absorber to expand and contract. For example, even if the hydraulic shock absorber is used as a vibration damper to prevent the building from being shaken by the wind, there is a concern that it cannot be realized.

  The present invention was devised in view of the above-described present situation, and the object of the present invention is to make it possible to exhibit a predetermined damping function depending on the expansion / contraction position while improving the installation property, and its versatility. It is an object of the present invention to provide a hydraulic shock absorber that is optimal for expecting an improvement in performance.

  In order to achieve the above object, the structure of the hydraulic shock absorber according to the present invention basically includes a cylinder body and both pressure chambers slidably housed in the cylinder body and paired in the cylinder body. And a piston body having a damping valve that allows communication between both pressure chambers, and a shaft end of the cylinder body is inserted from the closed end of the cylinder body while the base end is connected to the piston body. A rod body that protrudes to the outside, a bypass passage that is disposed outside the cylinder body and communicates both pressure chambers inside the cylinder body outside the cylinder body, and a control that is disposed in the bypass passage and enables opening and closing in the bypass passage A hydraulic valve having a valve and an input means for opening the control valve so as to follow the immersing operation of the rod body with respect to the cylinder body while facing the control valve with a space therebetween. In this device, the damping valves are arranged in parallel to allow communication in opposite directions in both pressure chambers, and the control valves are paired in opposite directions between both pressure chambers in the bypass passage. An input shaft that allows the control valve to input thrust from the input means facing the control valve to the tip, and a poppet that opens the bypass when retreating while being connected to the base end of the input shaft. The poppet has a base shaft having the same shaft diameter as the input shaft and a rear end in the atmosphere while the tip is connected to the poppet, and the poppet is urged by the urging force from the adjacent urging spring at the rear end of the base shaft. Assume that it is energized in the forward direction.

  Therefore, in the present invention, there is provided a damping valve in which a piston body that is slidably accommodated in the cylinder body and defines both pressure chambers in the cylinder body allows communication between both pressure chambers. Therefore, when the bypass path outside the cylinder body is blocked, a high damping force is generated by each damping valve during the expansion / contraction operation in which the rod body protrudes and retracts with respect to the cylinder body.

  In the present invention, the stroke of the rod body relative to the cylinder body is large, and therefore when there is an input from the input means to each pair of control valves, the bypass path is opened, At this time, each control valve allows communication in both pressure chambers in the cylinder body.

  As a result, the damping valve of the piston body that was maintained in a high damping force generation state until the bypass passage was opened by the operation of the control valve is the same as that until the bypass passage was opened by the operation of the control valve. The generated damping force is reduced.

  Then, when the piston body reverses in the cylinder body and shifts to the reverse stroke, and when the control valve releases its operation, the bypass path is shut off and a high damping force is generated by the damping valve of the piston body. The state will be guaranteed.

  In the present invention, the bypass path is formed outside the cylinder body, and each control valve for opening and closing the bypass path is opened and closed by input from the input means, so that the hydraulic shock absorber is in the neutral position. Regardless of whether or not, the interval between the input means and the control valve, that is, the dead zone stroke, which is the interval until the control valve is activated, can be set to be the same on the left and right.

  That is, when the hydraulic shock absorber according to the present invention is installed at an arbitrary place, there are various so-called installation intervals at the installation place. Therefore, in each hydraulic shock absorber, the piston body is brought into a completely neutral position within the cylinder body. Even if positioning is practically difficult, the neutral zone in the hydraulic shock absorber can be realized by making the dead zone stroke the same on both the left and right sides.

  As a result, in the present invention, when installing the hydraulic shock absorber, the neutral state in the hydraulic shock absorber can be surely revealed by visual operation, and a conventional type of hydraulic shock absorber is installed. As a result, the so-called neutral state is not easily displayed, and therefore it is possible to realize a quick installation work as compared with the case where it takes time to install the hydraulic shock absorber.

  In the present invention, the control valve for opening and closing the bypass path has a poppet that opens the bypass path when retreating while being connected to the proximal end of the input shaft that inputs the thrust from the input means facing the tip. Therefore, compared with the case where the opening and closing of the bypass passage is dependent on the spool, there is no need to worry about leakage of hydraulic oil.

  Further, in the present invention, in the control valve, since the input shaft which sandwiches the poppet and the base shaft whose rear end is opened to the atmosphere have the same shaft diameter, the poppet which is the opening operation of the control valve Therefore, it is possible to reduce the load on the input means for realizing the backward movement operation, and it is possible to make the input means light.

  Further, in the present invention, since the bypass path is provided outside the cylinder body in the hydraulic shock absorber and is not provided between the cylinder body and the piston body, a seal member such as a piston seal is interposed on the outer periphery of the piston body. Thus, it is possible to prevent the hydraulic oil from leaking between the cylinder body and the piston body.

  Hereinafter, the present invention will be described based on the illustrated embodiment. However, the hydraulic shock absorber according to the present invention is formed in a cylindrical shape and a double rod shape in the illustrated case, for example, each floor of a building. The vibration damper is disposed between the floor and the ceiling.

  As shown in FIG. 1, the hydraulic shock absorber includes both a cylinder body 1 and a pair of parts having the same cross-sectional area in the cylinder body 1 while being slidably housed in the cylinder body 1. A piston body 2 that defines a pressure chamber, that is, one pressure chamber R1 that is the upper side in the figure and the other pressure chamber R2 that is the lower side in the figure, A rod body 3 that is inserted through the shaft cores of the pressure chambers R1 and R2 and protrudes from the closed end of the cylinder body 1 to the outside. And the other rod body 32 on the lower side in the figure.

  In this hydraulic shock absorber, the piston body 2 has damping valves 21 and 22 that allow communication of both the pressure chambers R1 and R2, and the cylinder body 1 includes control valves 5 and 6 described later. The valve mount 4 that enables the arrangement of the valve mount 4 is integrally connected, and the valve mount 4 is a plate that is connected to the cylinder body 1 while having only a port (not shown). It consists of the part 41 and the main-body part 42 which is connected to this plate part 41 and has the control valves 5 and 6.

  By the way, the cylinder body 1 is formed of a so-called cylindrical body because the hydraulic shock absorber is a double rod type. In the drawing, the lower end side portion in the drawing has a sub-diameter having the same diameter as the cylinder body 1. The cylinder portion 11 is connected coaxially, and the tip end side which is the lower end side in the figure of the other rod body 32 is electrically connected to the sub cylinder portion 11, and the lower end side of the other rod body 32 is a so-called other portion. In addition, the sub-cylinder portion 11 includes a bracket 12 that enables so-called attachment of the hydraulic shock absorber.

  The piston body 2 itself is a damping valve that allows communication between both pressure chambers R1 and R2 defined in the cylinder body 1, that is, a damping valve 21 that is used for the expansion side, and a damping valve that is used for the pressure side. The valve 22 is arranged in parallel.

  At this time, the damping valves 21 and 22 are set so as to open when the upstream pressure exceeds the cracking pressure, and the cracking pressure is arbitrarily set.

  The rod body 3 has a bracket 33 at the tip of one of the rod bodies 31 that is upper in the drawing, and the hydraulic shock absorber can be attached using the bracket 33.

  Therefore, in this hydraulic shock absorber, attachment to a desired location using the brackets 12 and 33 described above is possible, that is, installation is possible. That is, so-called expansion / contraction operation is enabled.

  In this hydraulic shock absorber, if a bypass path, which will be described later, is ignored, assuming that the piston body 2 rises in the cylinder body 1 in the drawing, for example, during the extension side operation, one pressure chamber R1 communicates with the other pressure chamber R2 via the damping valve 21. At this time, a damping force having a predetermined magnitude is generated by the damping valve 21.

  Similarly, in this hydraulic shock absorber, assuming that the piston body 2 descends in the drawing in the cylinder body 1 in the drawing, for example, at the time of pressure side operation, the other pressure chamber R2 is connected via the damping valve 22 to one side. In this case, a damping force having a predetermined magnitude is generated by the damping valve 22.

  Next, in this hydraulic shock absorber, a bypass path (not shown) that bypasses the damping valves 21 and 22 provided in the piston body 2 and communicates both pressure chambers R1 and R2 outside the cylinder body 1. It is said to have.

  At this time, it is assumed that the so-called both ends of the bypass path communicate with the pressure chambers R1 and R2 in the cylinder body 1 at portions that become so-called stroke end regions in the pressure chambers R1 and R2.

  That is, even when the piston body 2 slides in the cylinder body 1 with a large stroke and approaches the end of the cylinder body 1, the opening opened in the cylinder body 1 is blocked. Accordingly, the communication between the pressure chambers R1 and R2 and the bypass is not hindered.

  On the other hand, the bypass path is formed in the valve mount 4 integrally connected to the cylinder body 1 in the drawing, that is, in the plate portion 41 and the main body portion 42 in the drawing. The control valves 5 and 6 are arranged in parallel so as to allow communication in opposite directions between the pressure chambers R1 and R2 while the main body 42 is a pair, and the flow direction of hydraulic oil in the bypass passage And check valves 7 and 8 for controlling.

  At this time, in view of the original function of the bypass path, it is assumed that the valve mount 4 is held by the cylinder body 1 regardless of whether it is formed on the valve mount 4. In a bowl, it would be preferable.

  That is, as will be described later, in the hydraulic shock absorber according to the present invention, the control valves 5 and 6 disposed in the bypass path are connected via the input means 9 but at the expansion / contraction position of the hydraulic shock absorber. Therefore, at least in the valve mount 4 having the control valves 5 and 6, this may be imitated by a part of the cylinder body 1. From this viewpoint, it is preferable that the valve mount 4 is integrally connected to the cylinder body 1 and held by the cylinder body 1.

  Each of the control valves 5 and 6 is opened by an input from the input means 9 following the movement of the rod body 3 with respect to the cylinder body 1. It is allowed to communicate with the room.

  That is, for example, in the control valve 5, when one rod body 31 is immersed in the cylinder body 1, it is switched to the open state by the input from the input means 9 during the pressure side operation, and the other pressure chamber R2 Is communicated with the one pressure chamber R1 through the opened control valve 5, and at this time, the control valve 6 is maintained in the closed state in its own state because the check valve 7 operates. As long as that is the case, the bypass is cut off.

  Even in the control valve 6, one rod body 31 protrudes from the inside of the cylinder body 1, so to speak, is switched to an open state by the input from the input means 9 during the extension side operation, and the one pressure chamber R 1 is The control valve 5 communicates with the other pressure chamber R2 via the opened control valve 6. At this time, the control valve 5 is operated by the check valve 8 in the same manner as described above. In the state, it is maintained in a closed state, and as long as it is closed, the bypass is blocked.

  As for the check valves 7 and 8, as described above, for example, when the control valve 5 is opened by the contraction of the hydraulic shock absorber in which one rod body 31 is immersed in the cylinder body 1, When the check valve 7 prevents the hydraulic oil in the pressure chamber R2 from flowing into the control valve 6 and the control valve 5 returns to the so-called return direction, that is, the rod body 31 extends from the inside of the cylinder body 1. When the hydraulic oil flowing out from the pressure chamber R1 in the cylinder body 1 flows into the control valve 5 that is not yet shut off, the check valve 8 prevents this, and the control valve 8 5 is maintained in a predetermined closed state, and only the damping valve 21 of the piston body 2 in the hydraulic shock absorber is operated to have a predetermined size. It will be 衰力 is generated.

  The hydraulic oil in the pressure chamber R1 in the cylinder body 1 flows into the control valve 5 when the control valve 6 is opened due to the extension of the hydraulic buffer in which one rod body 31 protrudes from the cylinder body 1. When the check valve 8 prevents the control valve 6 from returning, that is, by reversing the contraction in which one rod body 31 is immersed in the cylinder body 1, it flows out of the pressure chamber R <b> 2 in the cylinder body 1. The check valve 7 functions to prevent the hydraulic oil from flowing into the control valve 6 that has not yet been shut off, and to prevent the check valve 7 from being in a predetermined closed state. Only the damping valve 22 of the piston body 2 in the hydraulic shock absorber operates to generate a predetermined magnitude of damping force.

  From the above, according to the present invention, it is of course possible to adjust the level of the damping force generated by the hydraulic shock absorber by opening and closing the bypass path by the control valves 5 and 6. Also, due to the cooperation of the check valves 7 and 8, a displacement characteristic of the damping force as shown in FIG. 4 is obtained.

  Here, the control valves 5 and 6 will be described. Basically, as shown in FIG. 1, the control valves 5 and 6 include input shafts 51 and 61, poppets 52 and 62, and base shafts 53 and 63. The urging springs 54 and 64 are provided.

  That is, first, the input shafts 51 and 61 are used to input the thrust from the opposing input means 9 to the tip, and in the drawing, the axial direction is the same as that of the rod body 3 described above.

  In addition, the input shafts 51 and 61 have their tip portions that face the input means 9 projecting from the main body portion 42 of the valve mount 4 to the outside and are placed in the atmosphere. As shown in FIG. 2, the shaft length at the tip is adjustable, and the stroke amount for the input means 9 can be adjusted, that is, the dead zone strokes L1 and L2 described later can be adjusted. It is supposed to be.

  Note that, as shown in the figure, the input shafts 51 and 61 are provided with kerfs 51c and 61c as oil passages that realize flow rate control in accordance with displacement in spool portions that are forward portions of poppets 52 and 62 described later. A book or a plurality of books are formed.

  Next, the poppets 52 and 62 are connected to the base ends of the input shafts 51 and 61 and open the bypass when the input shafts 51 and 61 are retracted, and this is a so-called poppet. Compared with the case where this consists only of a so-called spool, there is no need to worry about leakage of hydraulic oil in the bypass passage.

  The base shafts 53 and 63 have the same diameter as that of the input shafts 51 and 61 while the front ends thereof are connected to the poppets 52 and 62, and the rear ends thereof are placed in the atmosphere. Since the leading ends of the input shafts 51 and 61 are also placed in the atmosphere while the rear end is placed in the atmosphere, the poppets 52 and 62 are maintained in the forward state only by a biasing force of biasing springs 54 and 64 described later. In other words, in this hydraulic shock absorber, the piston body 2 is allowed to slide in the cylinder body 1 while the bypass path is in the closed state. become.

  The urging springs 54 and 64 are made of coil springs in the drawing, but at this time, the urging forces of the urging springs 54 and 64 are not required to be the same unless the energizing forces are extremely small. is there.

  In the biasing springs 54 and 64, when the thrust from the input means 9 is input, the biasing springs 54 and 64 contract to allow the base shafts 53 and 63 to retract, that is, the poppets 52 and 62 retract. The passage of hydraulic oil around the poppets 52 and 62 is allowed.

  On the other hand, the input means 9 is formed so as to follow the movement of the rod body 3 described above. In the drawing, the arm member 91 connected to the one rod body 31 located in the upper side in the drawing. And a joint 92 that can be adjusted in length while being connected to the arm member 91, and an input main body 93 connected to the joint 92.

  At this time, the arm member 91 extends in a direction crossing the one rod body 31, and the joint 92 is directed downward from the front end of the arm member 91 in the drawing, that is, in the valve mount 4. The input main body portion 93 is connected to the lower end of the joint 92 and is close to the body posture so as to surround the main body portion 42 of the valve mount 4.

  That is, the input main body 93 is shown in the figure in which the control valves 5 and 6 cause the input shafts 51 and 61 to protrude in opposite directions to each other in the axial direction of the rod body 3. 42 is projected from the upper and lower ends of the input shafts 51 and 61, so that the input portions 93a and 93b facing the tips of the input shafts 51 and 61 are formed so as to have a so-called horizontal U-shape.

  The input portions 93a and 93b are opposed to the tips of the input shafts 51 and 61 while having dead zone strokes L1 and L2 between the control valves 5 and 6 and the tips of the input shafts 51 and 61, respectively. .

  Therefore, in this input means 9, for example, when one rod body 31 comes to be immersed in the cylinder body 1, the rod body 31 is immersed in the cylinder body 1 more than the dead zone stroke L 1. Until then, the input portion 93a does not interfere with the tip of the input shaft 51 in the control valve 5, and therefore, the control valve 5 does not open.

  When the stroke in which the rod body 31 is immersed in the cylinder body 1 is equal to or greater than the dead zone stroke L1, the input portion 93a causes the input shaft 51 in the control valve 5 to be immersed in the main body portion 42 in the valve mount 4. Accordingly, in the control valve 5, the poppet 52 is so-called retreated against the spring force of the biasing spring 54 to open.

  In addition, the above operation is the same as the input portion 93b on the opposite side of the input means 9 with respect to the input shaft 61 of the control valve 6 when the other rod body 32 comes into the cylinder body 1. Therefore, the control valve 6 operates in the same manner as the control valve 5 described above.

  As described above, in the hydraulic shock absorber according to the present invention, the amount of expansion / contraction exceeds the above-described dead zone strokes L1, L2 during the so-called expansion / contraction operation in which the rod body 3 protrudes and retracts with respect to the cylinder body 1. In other words, the corresponding control valves 5 and 6 are opened, so that the bypass path is switched to the communication state.

  Therefore, according to this, in the hydraulic shock absorber of the present invention, when the dead zone strokes L1 and L2 are the same, the hydraulic shock absorber is in a so-called neutral state.

  That is, when the hydraulic shock absorber is installed at an arbitrary location, so-called installation intervals at the installation location vary, and therefore, in the hydraulic shock absorber, the piston body 2 is positioned in a completely neutral position within the cylinder body 1. Even if it is practically difficult to determine, the so-called neutral position of the rod body 3 relative to the cylinder body 1 can be revealed by adjusting the dead zone strokes L1 and L2 to be the same. Will be.

  At this time, even if the piston body 2 is not in a completely neutral position in the cylinder body 1, in many cases, the deviation will not be unnecessarily large although it will be larger than the so-called tolerance. Therefore, it can be said that there is no problem even if it is assumed that the hydraulic shock absorber is in a neutral state by adjusting the dead zone strokes L1 and L2 to be the same.

  In view of the above, in the present invention, when installing the hydraulic shock absorber, it is possible to surely show the neutral state in the hydraulic shock absorber while visually confirming the neutral state. Therefore, it is not easy to make a so-called neutral state. Therefore, it is possible to realize a quick installation work as compared with the case where it takes time to install the hydraulic shock absorber.

  In order to be able to arbitrarily set the dead zone strokes L1, L2, for example, in the input means 9 described above, the arm member 91 is in the axial direction of the rod body 31 with respect to one rod body 31. The input main body 93 may have an expansion / contraction adjustment portion 93c at the intermediate portion so that the interval between the input portions 93a and 93b can be changed. .

  By the way, in the hydraulic shock absorber according to the present invention as described above, it is assumed that the control valves 5 and 6 have poppets 52 and 62, and the control valves 5 and 6 have only a so-called spool. Compared to the case, the leakage of hydraulic oil in the bypass passage can be effectively prevented.

  Therefore, the control valves 5 and 6 may be embodied in any manner as long as the poppets 52 and 62 are provided, but here, the control valves 5 and 6 are formed as shown in FIG.

  At this time, the configurations of the control valve 5 and the control valve 6 are basically the same. Therefore, as shown in FIG. Is omitted.

  That is, as shown in FIG. 2, the control valve 6 is disposed on the shaft core portion of the sleeve 43 that is disposed so as to be fitted into the valve body that is the main body portion 42 in the valve mount 4 (see FIG. 1). It is assumed that the plug 44 is screwed onto the valve body in the accommodated state to be fixed.

  At this time, the sleeve 43 is maintained in a so-called retaining state by abutting a locking portion 42 a formed so that a stepped portion 43 a on the left side in the drawing is opposed to the valve body. Under this condition, the tip of the plug 44 that is the left end in the drawing is screwed to the opening end that is the right side in the drawing of the valve body, so that the plug 44 is fixed in a fixed position. It is said.

  In the control valve 6, the valve body communicates with the communication hole 42 b communicating with the one pressure chamber R 1 in the cylinder body 1 (see FIG. 1) and the other pressure chamber R 2. It is assumed that the communication hole 42c is opened.

  Further, in the control valve 6, the sleeve 43 has a communication hole opened in the valve body, that is, a port 43b facing one communication hole 42b and a port 43c facing the other communication hole 42c. It is said to have.

  At this time, one port 43b is positioned on the so-called upstream side which is the left side in the drawing of the poppet 62, and the other port 43c is positioned on the so-called downstream side which is on the right side in the drawing of the poppet 62.

  Therefore, in this control valve 6, the hydraulic oil from the one pressure chamber R1 mentioned above flows into the upstream side of the poppet 62 via the communication hole 42b of the valve body and the port 43b of the sleeve 43. When 62 moves backward against the urging force of the urging spring 64 to cause a so-called flow path to appear, hydraulic oil flows into the back side of the poppet 62 through this flow path, and the port 43c of the sleeve 43 and the valve It flows into the other pressure chamber R2 through the body communication hole 42c.

  On the other hand, in this control valve 6, the input shaft 61 penetrates the shaft core portion on the left side in the drawing of the sleeve 43, and the tip portion that is the left end in the drawing is outside the sleeve 43, that is, It is said that it is put out of the valve body.

  At this time, the input shaft 61 has stroke adjusting means (not shown) formed in a so-called adjuster structure at the tip, and this stroke adjusting means is screwed into the tip of the input shaft 61 so as to be able to protrude and retract. It is assumed that the headed bolt 61a is fixed to the headed bolt 61 with a screwed lock nut 61b.

  Further, in this control valve 6, the input shaft 61 has a poppet 62 connected to the base end which is the right end in the figure, but gradually from the base end connected to the poppet 62 toward the front end side. The sleeve 43, which will be described later, has a kerf 61c as one or a plurality of oil passages facing the port 43b of the opening while deepening.

  Incidentally, the cut groove 61c as the oil passage is not exposed outside the sleeve 43, that is, outside the valve body when the poppet 62 is seated on a seat portion 43d described later.

  When the poppet 62 moves backward, the cut groove 61c as an oil passage immediately communicates with the front side of the poppet 62. As the backward movement amount of the poppet 62 increases, the deeper side of the so-called groove gradually becomes closer to the front side of the poppet 62. The flow rate of the hydraulic oil there is gradually increased.

  By the way, in view of the actual embodiment of the control valve 6, the poppet 62 described later is integrally formed between the input shaft 61 described above and the base shaft 63 described later, as shown in FIG. The so-called escape groove A and ring groove B of the tool are normally formed.

  Therefore, in consideration of the formation of the annular recess grooves A and B for escaping, the formation of the annular recess groove A is not limited to the annular recess groove B, but the starting point position of the cut groove 61c as the oil passage is described above. Compared with what is shown in FIG. 2, it starts from a position far from the tip of the poppet 62.

  As a result, in the case shown in FIG. 3, when the input shaft 61 is immersed in the valve mount 4 by the input from the input means 9, that is, the poppet 62 moves rightward in the drawing. When the seat part 43d described later is released, the bypass path is not opened, and the opening of the bypass path is started when hydraulic oil flows through the kerf 61c after dredging. Until then, a dead zone will be formed.

  Therefore, in the control valve 6 of the present invention, the kerf 61c is formed in the input shaft 61. In principle, the kerf 61c is continuous with the tip of the poppet 62 as shown in FIG. In consideration of the actual processing, it may be formed away from each other as shown in FIG.

  Next, in the control valve 6, the poppet 62 is formed so as to be converged in the left direction in the drawing, and the front end is integrally formed with the base end positioned in the sleeve 43 of the input shaft 61. In a so-called forward state, a so-called taper portion is detachably seated on a seat portion 43d, which is a step portion formed at a substantially central portion of the sleeve 43.

  Further, in the control valve 6, the base shaft 63 has a shaft diameter that is the same as that of the input shaft 61 while the tip which is the left end in the drawing is integrally connected to the rear surface of the poppet 62. It is assumed that the axial center part on the rear end side on the right side is inserted through the inside.

  At this time, the rear end portion which is the right end portion of the base shaft 63 in the drawing of the base shaft 63 passes through the shaft core portion of the tip portion of the plug 44, and between the plug 44 of the base shaft 63 and the sleeve 43 and the valve body. Although not shown between the plug 44 and between the plug 44 and the valve body, seal members are respectively provided to prevent so-called hydraulic fluid leakage.

  Further, an urging spring 64 made of a coil spring is accommodated in the shaft core portion of the plug 44, and the urging spring 64 has a through hole (not shown) in the shaft core portion and is plugged. 44, the cap 45 is screwed to the opening end which is the right end portion.

  At this time, the tip of the urging spring 64 that is the left end in the drawing is locked to a spring receiver 64a that is movably accommodated in the plug 44, and the shaft core portion of the spring receiver 64a includes The rear end portion of the base shaft 63 having a reduced diameter is inserted.

  The base end, which is the right end in the drawing of the urging spring 64, is carried by a spring receiver 64b that is also housed in the plug 44 and has a through hole (not shown) in the shaft core portion. The spring receiver 64b communicates the through holes of the spring receiver 64b with the cap 45 interposed therebetween.

  Therefore, in this control valve 6, as described above, the bypass passage is closed by the poppet 62. Therefore, compared with the case where the bypass passage is closed by the spool, there is no concern about leakage of hydraulic oil. Therefore, for example, when this hydraulic shock absorber is used as a damping damper to prevent the building from being shaken by the wind, this can be reliably realized.

  In the control valve 6, the input shaft 61 and the base shaft 63 sandwiching the poppet 62 have the same shaft diameter, the tip end of the input shaft 61 is placed in the atmosphere, and the rear end of the base shaft 63 is placed in the atmosphere. Therefore, in order to move the poppet 62 backward, it is only necessary to have an external input that overcomes the urging force of the urging spring 64.

  From this, it means that the spring force of the biasing spring 64 is sufficient to overcome the so-called friction when the control valve 6 is operated. Therefore, the high strength of the related parts due to the increased spring force. This is advantageous in that no high sealing performance is required.

  The above is an example of the case where the hydraulic shock absorber according to the present invention is used as a vibration damper in a building. However, from the point of view of the present invention, the hydraulic shock absorber according to the present invention is other than a building. Of course, for example, it may be used for vibration control of railway vehicles and equipment.

  In the above description, the present invention is embodied in a double rod type hydraulic shock absorber. However, from the point of view of the present invention, the present invention is embodied in a single rod type hydraulic shock absorber. Of course, any hydraulic shock absorber that uses a fluid other than gas, which is supposed to be non-shrinkable, can be realized.

  In the above description, the hydraulic shock absorber according to the present invention has been described by taking as an example the case where the valve mount 4 is integrally held by the cylinder body 1. However, in the hydraulic shock absorber according to the present invention, Even if the valve mount 4 is separated from the cylinder body 1, a neutral state in the hydraulic shock absorber can be realized.

  That is, regarding the installation of the hydraulic shock absorber at a predetermined position, the cylinder body 1 is first installed at the installation site in a state where it can be said that the cylinder body 1 is roughly viewed and is in a neutral state, and is separated from the cylinder body 1 after the dredging. If the valve mount 4 is moved and the dead zone strokes L1 and L2 are the same on the left and right sides, it can be said that a neutral state in the hydraulic shock absorber can be realized.

  Furthermore, in the hydraulic shock absorber according to the present invention, the control valves 5 and 6 are embodied, and since they are not formed on one axis but on two axes, this is mounted on the valve mount 4. In consideration of the case or the case where it is installed in the cylinder body 1, it is likely to hinder the miniaturization of the valve mount 4, or it may be difficult to make the installation in the cylinder body 1 disadvantageous. It can also be said that it is advantageous in that it can be avoided.

It is a figure which shows in principle the hydraulic shock absorber by one Embodiment of this invention. It is sectional drawing which shows one Embodiment of the control valve in FIG. It is the elements on larger scale which show other embodiment of the control valve shown in FIG. It is a figure which shows the displacement characteristic of the damping force by the damping valve which a piston body has.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder body 2 Piston body 3 Rod body 4 Valve mount 5,6 Control valve 7,8 Check valve 9 Input means 21,22 Damping valve 31 One rod body 32 The other rod body 51,61 Input shaft 52,62 Poppet 53 , 63 Base shaft 54, 64 Biasing spring R1, R2 Pressure chamber

Claims (5)

A piston body having a cylinder body and a damping valve that defines a pair of pressure chambers in the cylinder body while being slidably housed in the cylinder body and allows communication between the pressure chambers, and the piston A rod body that passes through the axial core of the pressure chamber while the base end is connected to the body and projects the tip from the closed end of the cylinder body to the outside, and both pressure chambers inside the cylinder body that are disposed outside the cylinder body A bypass passage communicating outside the body, a control valve disposed in the bypass passage and capable of opening and closing in the bypass passage, and an immersion operation of the rod body with respect to the cylinder body facing the control valve with a space therebetween In the hydraulic shock absorber having an input means for opening and opening the control valve following the movement,
While the damping valve is paired, it is arranged in parallel to allow communication in opposite directions in both pressure chambers, and the control valve is paired in communication in opposite directions between both pressure chambers in the bypass passage. A poppet that inputs the thrust from the input means facing the control valve to the tip, a poppet that is connected to the base end of the input shaft and opens the bypass when retreating, and the poppet And a base shaft having the same shaft diameter as the input shaft and having the rear end in the atmosphere, and the poppet is moved in the forward direction by a biasing force from a biasing spring provided adjacent to the rear end of the base shaft. A hydraulic shock absorber that is energized. The hydraulic shock absorber according to claim 1, wherein the bypass path is formed in a valve mount that is held by the cylinder body. The hydraulic shock absorber according to claim 1 or 2, wherein the input means has an input portion facing the control valve, and the interval between the input portion and the control valve is adjustable. 4. The hydraulic shock absorber according to claim 1, wherein the shaft length at the tip end portion of the input shaft in the control valve facing the input means is adjustable. 5. The check valve according to claim 1, wherein the control valve is provided with a check valve for preventing communication in a direction opposite to a communication direction between both pressure chambers permitted by the control valve. Hydraulic shock absorber.

Images