JP2019206266A - Suspension device - Google Patents

Abstract

To provide a suspension device which can be simply configured by reducing the number of attenuation force adjustment mechanisms provided in fluid pressure cylinders respectively and further make both vehicle steering stability and ride comfort compatible.SOLUTION: In a left hydraulic cylinder 1 at a front wheel side, a first fixed valve 10 is provided in a connection site between an upper chamber A and a first connection conduit path 8, and a first attenuation force adjustment mechanism 11 constituted of a two-way control valve is provided in a connection site between a lower chamber B and a second connection conduit path 9. In a right hydraulic cylinder 2 at the front wheel side, a second fixed valve 12 is provided in a connection site between the upper chamber A and the second connection conduit path 9, and a second attenuation force adjustment mechanism 13 constituted of a two-way control valve is provided in a connection site between the lower chamber B and the second connection conduit path 8. Further, in left and right hydraulic cylinders 3 and 4 at rear wheel sides, first and second fixed valves 16 and 18 and first and second attenuation force adjustment mechanisms 17 and 19 are provided in the same manner as the hydraulic cylinders 1 and 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a suspension device suitably used for buffering vibrations of, for example, a two-wheel or four-wheel vehicle.

  In general, in a vehicle such as a four-wheeled vehicle, a hydraulic cylinder is provided between the left and right wheels and the vehicle body, and vibrations in the upper and lower directions that occur during running, A suspension device configured to cushion roll vibration (rolling) or the like is known. As such a suspension device, there is a related suspension device in which the upper chamber and the lower chamber of the left and right hydraulic cylinders are piped in a cross in order to achieve both a rough road running performance and a good road maneuverability. (For example, refer to Patent Documents 1 and 2).

Japanese Patent No. 4675882 JP2015-120364A

  By the way, the suspension device according to the prior art can provide high roll rigidity when, for example, inputs of opposite phases occur with respect to the left and right wheels, but it does not necessarily improve the ride comfort of the vehicle when traveling on a rough road. There is a problem that it cannot be raised. In view of this, the present inventors have examined the provision of an electronically controlled damping force adjusting mechanism on the connection port side between the upper chamber and the lower chamber of each hydraulic cylinder. However, in this case, since a total of two damping force adjustment mechanisms are provided for one hydraulic cylinder, there is a problem that the entire structure becomes complicated and expensive.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension device that can reduce the number of damping force adjusting mechanisms provided in each hydraulic cylinder, simplify the structure, and achieve both vehicle handling stability and riding comfort. It is to provide.

  In order to solve the above-described problems, the suspension apparatus of the present invention employs a configuration in which the left, right, front, and rear wheels are interposed between the vehicle body and the vehicle body, and the inside of the cylinder is separated by the piston into the upper chamber and the lower chamber. Between the pair of hydraulic cylinders and the pair of hydraulic cylinders, the upper chamber of one hydraulic cylinder communicates with the lower chamber of the other hydraulic cylinder, and the upper portion of the other hydraulic cylinder The first and second connecting pipes are connected by a cross so that the chamber communicates with the lower chamber of the one hydraulic cylinder, and the first hydraulic cylinder is provided with a first adjustable hydraulic damping force. 1 damping force adjusting mechanism and a second damping force adjusting mechanism provided on the other hydraulic cylinder and capable of adjusting the damping force, wherein the first damping force adjusting mechanism is provided on the one hydraulic cylinder. It is provided to communicate with the lower chamber, and is expanded / contracted Each stroke is configured to be able to adjust the damping force, and the second damping force adjusting mechanism is provided so as to communicate with the lower chamber of the other hydraulic cylinder, and the damping force is adjusted for both the expansion and contraction strokes. It has a possible configuration.

  According to the present invention, the number of damping force adjusting mechanisms can be reduced, the structure can be simplified, and both the steering stability and the riding comfort of the vehicle can be achieved.

1 is an overall configuration diagram showing a suspension device according to an embodiment of the present invention. It is a longitudinal cross-sectional view which shows the specific structure of the hydraulic cylinder and damping force adjustment mechanism in FIG. It is a longitudinal cross-sectional view which expands and shows the damping force adjustment mechanism of FIG. It is a principal part enlarged view of the damping force adjustment mechanism shown in FIG. It is a control block diagram which shows the controller etc. which electronically control the 1st, 2nd damping force adjustment mechanism and bridge valve in FIG. It is a characteristic diagram which shows the damping-force characteristic of a damping-force adjustment mechanism by the expansion side and contraction side of a piston rod, respectively.

  Hereinafter, a suspension device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example the case of application to a four-wheeled vehicle.

  In FIG. 1, the left and right hydraulic cylinders (hereinafter referred to as the front wheel side left hydraulic cylinder 1 and the front wheel side right hydraulic cylinder 2) are the vehicle body and the left and right front wheels (both not shown). It is interposed between each. The rear left and right hydraulic cylinders (hereinafter referred to as rear wheel left hydraulic cylinder 3, rear wheel right hydraulic cylinder 4) are the vehicle body and the left and right rear wheels (both not shown). ) Between each other. In FIG. 1, the wheel positions of the vehicle are subscripted as a left front wheel (FL), a right front wheel (FR), a left rear wheel (RL), and a right rear wheel (RR).

  These hydraulic cylinders 1-4 are cylinder devices that are interposed between the vehicle body (on the spring) and each wheel (unsprung) of the vehicle, and expand and contract in accordance with the relative movement of the vehicle body and each wheel, A shock absorber for buffering the vibration of the vehicle is configured. For example, the left hydraulic cylinder 1 on the left front wheel side includes a cylinder 5 composed of a bottomed tubular tube, a piston 6 slidably fitted in the cylinder 5, and one end fixed to the piston 6 and the other end. The side includes a piston rod 7 protruding outside the cylinder 5. The cylinder 5 is defined by an upper and lower two chambers A and B (that is, an upper chamber A and a lower chamber B) by a piston 6.

  Similarly, the other hydraulic cylinders 2, 3, 4 are also configured to include a cylinder 5, a piston 6 and a piston rod 7. In each of the hydraulic cylinders 2, 3, 4, the inside of each cylinder 5 is defined by an upper chamber A and a lower chamber B by a piston 6.

  The first and second connecting pipes 8 and 9 are provided as a cross pipe between the left hydraulic cylinder 1 and the right hydraulic cylinder 2 on the front wheel side, and the two are connected by a cross. Of these, the first connection pipe line 8 extends left and right between the hydraulic cylinders 1 and 2 so as to communicate between the upper chamber A of the left hydraulic cylinder 1 and the lower chamber B of the right hydraulic cylinder 2. Are arranged. The second connecting pipe 9 is arranged extending left and right between the hydraulic cylinders 1 and 2 so as to communicate between the lower chamber B of the left hydraulic cylinder 1 and the upper chamber A of the right hydraulic cylinder 2. Has been.

  The left hydraulic cylinder 1 on the front wheel side is provided with a first fixed valve 10 at a connection site between the upper chamber A and the first connection pipe 8. The first fixed valve 10 has a damping valve that controls the damping force of the pressure oil flowing out from the upper chamber A toward the first connecting pipe 8 and attenuates the flow from the upper chamber A. The first fixed valve 10 also has a check valve 10A (see FIG. 2) that allows pressure oil to flow from the first connection pipe 8 toward the upper chamber A and prevents reverse flow. ing. That is, the first fixed valve 10 is provided at a position communicating with the upper chamber A of the left hydraulic cylinder 1, and the flow rate of the hydraulic fluid (pressure oil) flowing out from the upper chamber A toward the first connection pipe 8 is set. It is set as the structure which generates the damping force according to.

  The left hydraulic cylinder 1 on the front wheel side is provided with a first damping force adjusting mechanism 11 at a connection site between the lower chamber B and the second connection pipe 9. The first damping force adjusting mechanism 11 is configured as a bidirectional control valve (see FIGS. 2 and 3) as will be described later, and attenuates the pressure oil flowing out from the lower chamber B toward the second connecting conduit 9. It has a function of variably adjusting the force by electronic control and variably adjusting the damping force of the pressure oil flowing from the second connecting pipe 9 toward the lower chamber B by electronic control.

  In other words, the first damping force adjusting mechanism 11 is provided so as to communicate with the lower chamber B of the left hydraulic cylinder 1, and the damping force can be adjusted by electronic control in either the expansion stroke or the contraction stroke of the left hydraulic cylinder 1. It is configured as a bidirectional control valve. That is, the first damping force adjusting mechanism 11 is a damping that increases or decreases in response to an external command to the hydraulic fluid (pressure oil) flowing in and out between the lower chamber B of the left hydraulic cylinder 1 and the second connection pipe 9. It is configured to generate force.

  The right hydraulic cylinder 2 on the front wheel side is provided with a second fixed valve 12 at a connection site between the upper chamber A and the second connection pipe 9. The second fixed valve 12 is configured in the same manner as the first fixed valve 10 described above, and controls the damping force of the pressure oil flowing out from the upper chamber A of the right hydraulic cylinder 2 toward the second connection pipe 9. . The second fixed valve 12 is provided at a position that communicates with the upper chamber A of the right hydraulic cylinder 2, and the hydraulic fluid (pressure oil) that flows out from the upper chamber A toward the second connection pipe 9 corresponds to the flow rate. A predetermined damping force is generated.

  Further, the right hydraulic cylinder 2 on the front wheel side is provided with a second damping force adjusting mechanism 13 at a connection portion between the lower chamber B and the first connection pipe 8. The second damping force adjusting mechanism 13 is configured as a bidirectional control valve (see FIGS. 2 and 3), similar to the first damping force adjusting mechanism 11 described above. The second damping force adjustment mechanism 13 variably adjusts the damping force of the pressure oil flowing out from the lower chamber B toward the first connection pipe line 8 by electronic control, and from the first connection pipe line 8 to the lower chamber. It has a function to variably adjust the damping force of the pressure oil flowing toward B by electronic control.

  In other words, the second damping force adjusting mechanism 13 is provided so as to communicate with the lower chamber B of the right hydraulic cylinder 2, and is configured as a bidirectional control valve capable of adjusting the damping force in either the expansion stroke or the contraction stroke. ing. That is, the second damping force adjustment mechanism 13 is a damping that increases or decreases in response to an external command to the hydraulic fluid (pressure oil) flowing in and out between the lower chamber B of the right hydraulic cylinder 2 and the first connection pipe 8. The force is variably generated by electronic control.

  The left hydraulic cylinder 3 and the right hydraulic cylinder 4 on the rear wheel side are cross-connected by first and second connection pipes 14 and 15 as cross pipes. That is, the first connection pipe line 14 extends left and right between the hydraulic cylinders 3 and 4 so as to communicate between the upper chamber A of the left hydraulic cylinder 3 and the lower chamber B of the right hydraulic cylinder 4. Are arranged. The second connection pipe line 15 is arranged extending left and right between the hydraulic cylinders 3 and 4 so as to communicate between the lower chamber B of the left hydraulic cylinder 3 and the upper chamber A of the right hydraulic cylinder 4. Has been.

  In the left hydraulic cylinder 3 on the rear wheel side, a first fixed valve 16 is provided at a connection portion between the upper chamber A and the first connection pipe line 14, and the connection between the lower chamber B and the second connection pipe line 15 is provided. A first damping force adjusting mechanism 17 is provided at the site. The first fixed valve 16 is configured in the same manner as the first fixed valve 10 described above, and the first damping force adjusting mechanism 17 is configured in the same manner as the first damping force adjusting mechanism 11 described above.

  The right hydraulic cylinder 4 on the rear wheel side is provided with a second fixed valve 18 at a connection portion between the upper chamber A and the second connection line 15, and the connection between the lower chamber B and the first connection line 14 is provided. A second damping force adjusting mechanism 19 is provided at the site. The second fixed valve 18 is configured in the same manner as the above-described second fixed valve 12, and the second damping force adjusting mechanism 19 is configured in the same manner as the above-described second damping force adjusting mechanism 13.

  Next, the front side communication path 20 is a pipe line that communicates and blocks between the first and second connection pipe lines 8 and 9 via a bridge valve 21 on the front wheel side. The front wheel side bridge valve 21 is constituted by, for example, a normally closed electromagnetic valve, and is normally in a valve closing position (not shown) so as to block the flow of pressure oil (liquid) along the front communication path 20. Retained. However, when the valve 70 is switched from the valve closing position to the valve opening position (not shown) by energization from the controller 70 which will be described later, the bridge valve 21 causes the pressure oil to flow forward between the first and second connection pipelines 8 and 9. Allow distribution through the communication path 20. Therefore, while the bridge valve 21 is open, the hydraulic cylinders 1 and 2 are in a state in which the upper chamber A and the lower chamber B communicate with each other via the bidirectional control valve, the fixed valve, and the check valve 10A. .

  On the other hand, the rear side communication path 22 is a pipe line that communicates and blocks between the first and second connection pipe lines 14 and 15 via a bridge valve 23 on the rear wheel side. The rear-wheel-side bridge valve 23 is configured by an electromagnetic valve in the same manner as the front-wheel-side bridge valve 21 and is normally closed so as to block the flow of pressure oil (hydraulic fluid) along the rear-side communication path 22. Held in position. However, when the valve 70 is switched to the open position by energization from the controller 70 which will be described later, the bridge valve 23 causes the pressure oil to flow between the first and second connection pipes 14 and 15 via the rear connection path 22. I forgive you. Therefore, while the bridge valve 23 is switched to the valve open position, the hydraulic cylinders 3 and 4 on the rear wheel side are in a state where the upper chamber A and the lower chamber B communicate with each other.

  The right communication passage 24 is a conduit that always connects the front connection pipe 8 and the rear connection pipe 14 at a position close to the right hydraulic cylinder 2 on the front wheel side and the right hydraulic cylinder 4 on the rear wheel side. . The left communication passage 25 is a conduit that always connects the front connection line 9 and the rear connection line 15 at a position close to the left hydraulic cylinder 1 on the front wheel side and the left hydraulic cylinder 3 on the rear wheel side. .

  In the middle of the right communication path 24, an accumulator 26 and a throttle valve 27 as a pressure accumulator are provided. Similarly, an accumulator 26 and a throttle valve 27 are provided in the middle of the left communication path 25. Each throttle valve 27 generates a damping force due to a throttle resistance when pressure oil (working fluid) flows in and out (circulates) between the communication passages 24 and 25 and the accumulator 26, respectively. 4 telescopic movement is buffered. The hydraulic cylinders 1 to 4, the connection pipes 8, 9, 14, 15 and the communication passages 24 and 25 are filled with hydraulic oil (liquid as a working fluid).

  Next, specific configurations of the hydraulic cylinders 1 to 4, the first damping force adjustment mechanisms 11 and 17, and the second damping force adjustment mechanisms 13 and 19 will be described with reference to FIGS. 2 to 4. The specific structures of the hydraulic cylinders 1 to 4 are substantially the same, and the specific structures of the first damping force adjusting mechanisms 11 and 17 and the second damping force adjusting mechanisms 13 and 19 are substantially the same. The same as above.

  Therefore, in the following description, the left hydraulic cylinder 1 and the first damping force adjustment mechanism 11 on the front wheel side will be described as representative examples, and the other hydraulic cylinders 2 to 4, the second damping force adjustment mechanisms 13 and 19, and The description of the first damping force adjusting mechanism 17 is omitted.

  In FIG. 2, the cylinder 5 of the hydraulic cylinder 1 (2-4) is formed as a double cylinder composed of an inner cylinder 5A and an outer cylinder 5B, and a rod guide for supporting the piston rod 7 movably on the bottom side thereof. 28 is provided. A mounting member 29 (that is, a mounting eye) for mounting the hydraulic cylinder 1 (2 to 4) on the wheel side is provided on the projecting end side of the piston rod 7 projecting downward from the cylinder 5 through the rod guide 28. It has been.

  The inner cylinder 5A of the cylinder 5 is provided with an oil hole 30 that always communicates with the lower chamber B of the piston 6. An annular oil passage 31 is formed between the inner cylinder 5A and the outer cylinder 5B, and this oil passage 31 is always in communication with the lower chamber A of the piston 6 through the oil hole 30. An attachment member 32 for attaching the damping force adjusting mechanism 11 is provided on the upper end (one end) side of the cylinder 5.

  The attachment member 32 includes a connecting cylinder 32A extending upward and downward between the cylinder 5 and the damping force adjusting mechanism 11, and an inner side arranged in a double cylinder structure inside the connecting cylinder 32A. The pipe 32B and a cap 32C that covers the upper end side of the inner cylinder 5A are included. The lower end side of the connecting cylinder 32A is fixed to the cylinder 5 so as to cover the upper end side of the outer cylinder 5B from above. The lower end side of the inner pipe 32B is connected to the cap 32C. The lower end side of the inner pipe 32B always communicates with the upper chamber A in the cylinder 5 via the cap 32C. Between the connecting cylinder 32 </ b> A of the attachment member 32 and the inner pipe 32 </ b> B is another oil passage 33 that communicates with the oil passage 31 in the cylinder 5.

  The mounting plate 34 as the vehicle body side mounting member is fixedly mounted on the outer peripheral side of the connecting cylindrical body 32 </ b> A via the mount rubber 35. The mounting plate 34 is provided with a plurality of mounting bolts 36 (only one is shown) at intervals in the circumferential direction. The attachment plate 34 is attached to the vehicle body side together with the hydraulic cylinders 1 (2 to 4) by fastening the attachment bolts 36 to the vehicle body side via nuts (not shown). Further, the upper end side of a rack spring (hereinafter referred to as a spring 37) is in contact with the lower surface side of the mounting plate 34 in an elastically deformed state.

  The lower end side of the spring 37 is supported by a spring receiver 39 provided on the outer peripheral side of the upper end of the rod cover 38. The rod cover 38 is formed as a stepped cylindrical body that surrounds the periphery of the piston rod 7, and is fixed to the lower end (projecting end) side of the piston rod 7 by means such as welding. For this reason, the rod cover 38 is movable upward and downward in accordance with the expansion and contraction operation of the piston rod 7.

  The spring 37 is elastically deformed in accordance with the relative displacement between the mounting plate 34 and the rod cover 38 (the expansion and contraction operation of the hydraulic cylinder 1), and always urges the piston rod 7 in the extending direction (projecting direction). The hydraulic cylinder 1 (2 to 4) is provided with a dust cover 40 that is positioned between the cylinder 5 and the spring 37 and can be expanded and contracted upward and downward. The dust cover 40 is displaced upward and downward together with the rod cover 38 in order to prevent external dust, stepping stones, and the like from colliding with and adhering to the outer peripheral surface of the piston rod 7, for example.

  The first damping force adjusting mechanism 11 has a cylindrical valve housing 41 attached to the upper end (one end) side of the attachment member 32 using means such as screwing. The valve housing 41 is provided with a large-diameter chamber 41A in which a solenoid case 42 and a piston 43 (defining member) and the like are accommodated, a one-side connection port 41B that communicates with the large-diameter chamber 41A and opens sideways. A small-diameter chamber 41C that is fitted and attached to the inner pipe 32B of the member 32 and communicates with the upper chamber A of the cylinder 5 and an other-side connection port 41D that communicates with the small-diameter chamber 41C and opens sideways are provided. .

  The valve housing 41 is spaced apart in the radial direction of the small-diameter chamber 41C and extends upward and downward, and the large-diameter chamber 41A is always in communication with the oil passage 33 of the mounting member 32 (that is, the lower chamber B of the cylinder 5). A passage 41E is provided. As shown in FIG. 2, for example, a second connection pipe 9 is connected to one side connection port 41 </ b> B of the valve housing 41. On the other hand, for example, the first connection pipe line 8 is connected to the other side connection port 41 </ b> D of the valve housing 41 via the first fixed valve 10.

  The first damping force adjusting mechanism 11 includes a solenoid case 42 that is inserted into the large-diameter chamber 41A of the valve housing 41 by means such as screwing, and a definition that is inserted into the large-diameter chamber 41A. A piston 43 serving as a member, and a cylindrical rod 44 that is fixed to the opening (lower end) side of the solenoid case 42 and holds the piston 43 in a state of being fixed in the large-diameter chamber 41A of the valve housing 41. ing.

  The piston 43 defines the inside of the large-diameter chamber 41A of the valve housing 41 into two chambers C and D (hereinafter referred to as oil chambers C and D). For example, the oil chamber C located below the piston 43 is always in communication with the lower chamber B in the cylinder 5 through the passage 41E and the oil passages 31 and 33. Further, the oil chamber D located on the upper side of the piston 43 is always in communication with the second connection conduit 9 via the one side connection port 41B.

  The first damping force adjusting mechanism 11 is the first in which pressure oil as hydraulic fluid flows when the piston 6 moves in the cylinder 5 of the hydraulic cylinder 1 (that is, the piston rod 7 extends and contracts from the cylinder 5). A passage (for example, oil passages 43A and 43B of the piston 43) and a second passage provided in parallel with the first passage (for example, the inner passage 44F of the cylindrical rod 44, the passages 63B and 63C of the movable valve seat 63, Valve chamber E, oil passage 44D, annular recess 54A of valve seat member 54, and the like, and damping force valves 49 and 55 that are arranged in the first passage and suppress the flow of the pressure oil to generate a damping force. It is configured to include.

  Further, the first damping force adjusting mechanism 11 includes a compression side damping force generation unit 47 including a back pressure chamber 51 (described later) for applying an internal pressure to the compression side damping force valve 49 in the valve closing direction, a solenoid 58 (described later), and And an expansion side damping force generating portion 53 in which the pressure in the second passage (for example, in the valve chamber E of the movable valve seat 63) is variably adjusted by the poppet valve body 65 and the damping force is variable. The contraction-side damping force generation unit 47 is configured so that the pressure in the second passage (for example, in the valve chamber E of the movable valve seat 63) is variably adjusted by the solenoid 58 and the poppet valve body 65, thereby (The back pressure of the damping force valve 49) changes. Therefore, the generated damping force of the compression side damping force valve 49 is variably adjusted by the magnetic force of the solenoid 58.

  As shown in FIGS. 3 and 4, the piston 43 is formed with a plurality of oil passages 43 </ b> A and 43 </ b> B that can communicate with the oil chamber D and the oil chamber C, respectively, spaced apart in the circumferential direction. These oil passages 43A and 43B constitute a first passage through which pressure oil flows between the two oil chambers C and D in the large-diameter chamber 41A. On one end (upper) end face of the piston 43, there is an annular recess 43C formed so as to surround the one side opening of the oil passage 43A, and a damping force valve 55, which will be described later, is located on the radially outer side of the annular recess 43C. An annular valve seat 43 </ b> D for separating and seating is provided. On the other side (lower side) end surface of the piston 43, an annular recess 43E formed so as to surround the other side opening of the oil passage 43B, and a damping force valve 49, which will be described later, are located on the radially outer side of the annular recess 43E. An annular valve seat 43F on which the (main disk 49A) is seated is provided.

  As shown in FIG. 4, the cylindrical rod 44 has a bottomed cylindrical large-diameter cylindrical portion 44A in which a movable valve seat 63 described later is accommodated, and a bottom 44B of the large-diameter cylindrical portion 44A. And a cylindrical small-diameter rod portion 44 </ b> C extending in the horizontal direction. The piston 43 is fixed to the small-diameter rod portion 44 </ b> C by a nut 46 through a spacer 45 and damping force generation portions 47 and 53.

  The large-diameter cylindrical portion 44A of the cylindrical rod 44 is fixed to the solenoid case 42 by means of caulking or the like with the opening end side (the upper end side in FIG. 4) fitted to the opening side of the solenoid case 42. Has been. The large-diameter cylindrical portion 44A of the cylindrical rod 44 is formed with a plurality of oil passages 44D extending through the bottom 44B in the upward and downward directions. These oil passages 44 </ b> D constitute a part of the second passage that allows an annular recess 54 </ b> A and a through hole 54 </ b> B of a valve seat member 54 to be described later to communicate with the valve chamber E of the movable valve seat 63.

  On the other hand, the small-diameter rod portion 44C of the cylindrical rod 44 is formed with a concave groove 44E as a back pressure (pilot pressure) introduction passage that extends in the axial direction along the outer peripheral surface and communicates with a back pressure chamber 51 described later. ing. The recessed groove 44E is a passage that allows communication between the back pressure chamber 51 and the annular recessed portion 54A of the valve seat member 54 via oil guide passages 52 and 57, which will be described later. The inner peripheral side of the small-diameter rod portion 44C is an inner passage 44F that always communicates with the oil chamber C, and the inner passage 44F constitutes a part of the second passage.

  The nut 46 attaches the piston 43 to the small-diameter rod portion 44C of the cylindrical rod 44 in a screwed state, and attaches and detaches the compression side and extension side damping force generation portions 47 and 53 (described later) on the upper and lower surfaces of the piston 43. It is fastened and fixed as possible.

  As shown in FIG. 4, the contraction-side damping force generating portion 47 is positioned in the oil chamber C of the large-diameter chamber 41 </ b> A and is fixedly attached to the lower side of the piston 43. When the piston 6 slides upward in the cylinder 5 during the contraction stroke of the piston rod 7 shown in FIG. 2, the contraction-side damping force generator 47 generates hydraulic oil (pressure oil) from the annular oil passages 31 and 33 side. ) In the lower chamber B, a resistance force is applied to the pressure oil flowing from the oil chamber D of the valve housing 41 to the oil chamber C through the oil passages 43A, the annular recesses 43E, etc. of the piston 43, As will be described later, the damping force on the contraction side is generated with characteristics according to the control command.

  Here, the contraction-side damping force generating portion 47 is located between the piston 43 and the spacer 45 and fixed to the outer peripheral side of the cylindrical rod 44 (small-diameter rod portion 44C), and a plurality of discs. A damping force valve 49 including a valve and a relief disk valve 50 are included. The damping force valve 49 has an elastic seal member 49B (described later) that is fitted to the lower surface side of the pilot case 48 (an inner peripheral surface of a cylinder portion 48B described later) with a tightening margin. It is a first valve that forms the pressure chamber 51.

  The pilot case 48 of the compression side damping force generating portion 47 includes an annular plate portion 48A fitted to the outer peripheral side of the small-diameter rod portion 44C, and an upward direction from the outer peripheral side of the annular plate portion 48A to one side in the axial direction. A short cylindrical portion 48B extending to the annular plate portion 48A, an annular concave portion 48C formed on the lower surface of the annular plate portion 48A and opened and closed by the relief disk valve 50, and the short cylindrical portion 48B inside the annular concave portion 48C. A plurality of through-holes 48D are formed so as to be communicated with each other, and are formed in an intermediate portion in the radial direction of the annular plate portion 48A and opened downward.

  The relief disc valve 50 is provided between the spacer 45 and the pilot case 48 on the outer peripheral side of the small-diameter rod portion 44C, and normally closes the annular recess 48C of the pilot case 48. However, the pressure (pilot pressure) in the back pressure chamber 51 communicating with the annular recess 48C through the through hole 48D is higher than the valve opening set pressure of the relief disk valve 50 (the valve opening set pressure of the damping force valve 49). When the pressure rises to a high pressure), the relief disk valve 50 is opened from the end face of the pilot case 48, and functions as a safety valve that relieves excess pressure at this time to the oil chamber D side.

  The damping force valve 49 includes a main disk 49A that is attached to and detached from the annular valve seat 43F of the piston 43, and an annular elastic seal member that is fixed to the outer peripheral side of the lower surface of the main disk 49A by means of vulcanization or baking. 49B. The elastic seal member 49B is formed in a thick ring shape using an elastic material such as rubber, and the inner back pressure chamber 51 (that is, the inner peripheral surface of the cylinder portion 48B) is formed with respect to the outer oil chamber C. Are sealed in a liquid-tight manner.

  Between the pilot case 48 and the damping force valve 49 of the compression side damping force generation unit 47, an oil guide path 52 that always communicates with the back pressure chamber 51 is provided. The oil guide passage 52 constitutes a pilot pressure (back pressure) introduction passage together with the concave groove 44 </ b> E of the cylindrical rod 44. The damping force valve 49 is, for example, an opening whose pressure difference between the oil chamber D (annular recess 43E) and the back pressure chamber 51 (that is, the inner peripheral side of the cylinder portion 48B) is determined in the contraction stroke of the piston rod 7. When the valve set pressure is increased, the main disk 49A is separated from the annular valve seat 43F and generates a compression side damping force. When the damping force valve 49 (main disk 49A) is opened, the oil chamber D and the oil chamber C communicate with each other via the oil passage 43A of the piston 43.

  The concave groove 44E of the cylindrical rod 44 (small diameter rod portion 44C) communicates with the oil chamber D via an annular recess 54A and an orifice 56A of a valve seat member 54, which will be described later, and the valve chamber of the movable valve seat 63. E also communicates with the cylindrical rod 44 through an oil passage 44D and the like. For this reason, when the damping force valve 49 (main disk 49A) is closed, the pressure in the concave groove 44E of the cylindrical rod 44 (small-diameter rod portion 44C) and the back pressure chamber 51 is, for example, a solenoid 58 and a poppet valve body to be described later. 65 is variably adjusted according to the pressure in the valve chamber E. As a result, the pressure in the back pressure chamber 51 (back pressure of the damping force valve 49) changes, and the damping force valve 49 on the contraction side is variably adjusted by the magnetic force of the solenoid 58.

  As shown in FIG. 4, the extension-side damping force generator 53 is positioned in the oil chamber D of the large-diameter chamber 41 </ b> A and is fixedly attached to the upper side of the piston 43. The extension-side damping force generating portion 53 is annularly formed from the lower chamber B to the oil chamber C of the valve housing 41 when the piston 6 slides downward in the cylinder 5 during the extension stroke of the piston rod 7 shown in FIG. A resistance force is applied to the hydraulic oil (pressure oil) flowing out through the oil passages 31, 33, etc., and an elongation-side damping force is generated with characteristics according to a control command as will be described later.

  Here, the extension-side damping force generating portion 53 is positioned between the bottom portion 44B of the cylindrical rod 44 and the piston 43, and is fixed to the outer peripheral side of the small-diameter rod portion 44C. The damping force valve 55 and the check disc valve 56 are configured. The valve seat member 54 is formed as an annular plate, and is fitted to the outer peripheral side of the small-diameter rod portion 44C. The valve seat member 54 has an annular recess 54A formed on its lower surface and opened and closed by a check disc valve 56, and a valve seat so that the annular recess 54A communicates with the oil passage 44D of the cylindrical rod 44. A plurality of through-holes 54 </ b> B are formed in the middle portion in the radial direction of the member 54 and open upward and downward.

  The damping force valve 55 normally sits on the annular valve seat 43D of the piston 43, and blocks the pressure oil from the oil chamber C from flowing into the oil chamber D through the oil passage 43B of the piston 43. However, when the pressure in the annular recess 43C increases to a predetermined valve opening set pressure, the damping force valve 55 is separated from the annular valve seat 43D to generate an extension side damping force. That is, when the damping force valve 55 is opened, the oil chamber C and the oil chamber D communicate with each other via the oil passage 43 </ b> B of the piston 43. At this time, the pressure oil flowing from the oil chamber C of the valve housing 41 to the oil chamber D through the oil passages 43B and the annular recesses 43C of the piston 43 is given a resistance force by the damping force valve 55, and is expanded. Generates a damping force.

  The check disc valve 56 is provided between the valve seat member 54 and the damping force valve 55 on the outer peripheral side of the small diameter rod portion 44C, and normally closes the annular recess 54A of the valve seat member 54. . However, since the pressure in the annular recess 54A communicates with the inside of the valve chamber E of the movable valve seat 63 via the through hole 54B of the valve seat member 54, the pressure in the valve chamber E rises as described later. The check disc valve 56 opens from the lower surface of the valve seat member 54 and has a function of relieving the pressure on the valve chamber E side of the movable valve seat 63 to the oil chamber D side.

  In addition, the check disc valve 56 is formed with an orifice 56 </ b> A that constantly communicates between the annular recess 54 </ b> A of the valve seat member 54 and the outer oil chamber D. The orifice 56A gives a squeezing resistance to the pressure oil flowing through the orifice 56A between the annular recess 54A of the valve seat member 54 and the oil chamber D even when the check disc valve 56 is closed. This produces a damping force of the orifice characteristic. The orifice 56A is not necessarily provided in the check disc valve 56. For example, the orifice 56A may be provided on the lower surface side of the valve seat member 54 so as to communicate with the annular recess 54A.

  Further, between the valve seat member 54 of the extension side damping force generating portion 53 and the check disc valve 56, there is an oil guide passage 57 that communicates the inside of the annular recess 54A with the recess groove 44E of the cylindrical rod 44. Is provided. The oil guide passage 57 constitutes a pilot pressure (back pressure) introduction passage together with the recessed groove 44E of the cylindrical rod 44 and the oil guide passage 52 on the back pressure chamber 51 side. The pressure in the back pressure chamber 51 (pilot pressure) is variable according to the pressure in the annular recess 54A of the valve seat member 54, that is, the pressure on the valve chamber E side of the movable valve seat 63 that is electromagnetically changed by an external command. Set to

  Next, the solenoid case 42 in the valve housing 41 constitutes the outer shell of a solenoid 58 used as a variable damping force actuator. The solenoid 58 includes a coil 60 that generates a magnetic force when energized via an external cable 59, a stepped cylindrical stator core 61 provided on the inner peripheral side of the coil 60, and an inner peripheral side of the stator core 61. And a cylindrical mover 62 movably provided in the axial direction (upward and downward).

  On the inner peripheral side of the stator core 61, a cylindrical movable valve seat 63 is slidably provided on the lower side of the mover 62 so as to be coaxial. The movable valve seat 63 is always urged downward by an urging spring 66 described later via an operating pin 64 and a poppet valve body 65. Thereby, the lower surface of the movable valve seat 63 is seated on the bottom portion 44B of the cylindrical rod 44, and the inner passage 44F of the cylindrical rod 44 is blocked (blocked) from the inside of the large-diameter cylindrical portion 44A.

  At the center side of the movable valve seat 63, there is provided a bottomed hole portion 63A in which the poppet valve body 65 can be detached and attached. The bottomed hole portion 63A is opened and closed by the poppet valve body 65. A valve chamber E is formed. This valve chamber E (bottomed hole 63A) is always in communication with the oil passage 44D of the cylindrical rod 44 through a radial passage 63B formed in the movable valve seat 63. The movable valve seat 63 is provided with an axial passage 63C that is spaced apart in the radial direction of the bottomed hole 63A (valve chamber E). The passage 63C is opened when the poppet valve body 65 is opened. It communicates with the chamber E (passage 63B). When the poppet valve body 65 is closed, the valve chamber E (passage 63B) is blocked from the passage 63C.

  The operating pin 64 formed of a magnetic material is disposed on the inner peripheral side of the mover 62 so as to be relatively displaceable, and is always urged downward by the spring force of the urging spring 66. The operating pin 64 has a small-diameter shaft portion 64A extending in the axial direction and having a lower end formed in a hemispherical shape, and a poppet valve body 65 is positioned and arranged in a contact state at the lower end portion of the small-diameter shaft portion 64A. Yes. Another spring 67 is disposed between the poppet valve body 65 and the movable valve seat 63, and this spring 67 connects the movable valve seat 63 and the poppet valve body 65 with a spring force smaller than that of the biasing spring 66. They are biased in opposite directions (up and down). Further, a weak spring 68 that biases the poppet valve body 65 toward the bottomed hole 63 </ b> A of the movable valve seat 63 is disposed between the lower surface of the movable element 62 and the poppet valve body 65. The weak spring 68 is set to have a smaller spring force than the other springs 67.

  Here, the poppet valve body 65 is urged downward via the operating pin 64 by the urging spring 66 so as to close the bottomed hole 63A of the movable valve seat 63 from above, and the valve chamber E of the movable valve seat 63 Is cut off from the inner passage 44F side of the cylindrical rod 44 (small-diameter rod portion 44C). However, when a magnetic force is generated in the coil 60 of the solenoid 58 by energization from the outside, the operating pin 64 and the poppet valve body 65 are attracted upward against the biasing spring 66 by the magnetic force at this time. Therefore, the poppet valve body 65 opens the valve chamber E of the movable valve seat 63 with a lift amount proportional to the energization amount (current value), and between the passages 63B and 63C of the movable valve seat 63, that is, inside the cylindrical rod 44. The passage 44F, the oil passage 44D, and the annular recess 54A of the valve seat member 54 are communicated with each other via the valve chamber E.

  Next, the controller 70 shown in FIG. 5 is configured by, for example, a microcomputer and the like, and controls to electronically control the first damping force adjusting mechanisms 11 and 17, the second damping force adjusting mechanisms 13 and 19, the bridge valves 21 and 23, and the like. Device. The controller 70 is connected to the temperature sensor 71, the pressure sensor 72, the steering angle sensor 73, the vehicle speed sensor 74, the lateral acceleration sensor 75, and the like on the input side, and the first damping force adjusting mechanisms 11 and 17 and the second damping force adjusting mechanism on the output side. 13, 19 and bridge valves 21, 23 and the like. The controller 70 has a memory 70A composed of, for example, a ROM, a RAM, a nonvolatile memory, and the like.

  The memory 70A of the controller 70 is used to control switching of the bridge valves 21 and 23 and / or the solenoid 58 and the like of the first damping force adjusting mechanisms 11 and 17 and the second damping force adjusting mechanisms 13 and 19. A processing program (not shown) and the like are stored. That is, the controller 70 performs switching control of the bridge valves 21 and 23 according to the driving state of the vehicle in order to variably adjust the roll rigidity of the vehicle. Further, control is performed to variably adjust the damping force by the first damping force adjusting mechanisms 11 and 17 and the second damping force adjusting mechanisms 13 and 19 in either the expansion stroke or the contraction stroke of the hydraulic cylinders 1 to 4.

  In other words, the first damping force adjusting mechanism 11 sends a hydraulic fluid (pressure oil) flowing in and out between the lower chamber B of the left hydraulic cylinder 1 and the second connecting pipe 9 to an external command from the controller 70. A damping force that increases or decreases in response to this is variably generated. Further, the other damping force adjusting mechanisms 13, 17, 19 are also used as hydraulic fluid (pressure oil) flowing in and out between the lower chamber B of the hydraulic cylinders 2, 3, 4 and the connection pipes 8, 9. A damping force that increases or decreases according to an external command from the controller 70 is variably generated.

  For example, the temperature sensor 71 detects the temperature of the hydraulic fluid flowing in the connection pipes 8 and 9 shown in FIG. 1 and outputs a detection signal to the controller 70. The pressure sensor 72 detects, for example, the pressure in the connection pipe lines 8 and 9 and outputs the detection signal to the controller 70. The steering angle sensor 73 detects the steering angle of a steering handle (not shown) during the steering operation (turning operation) of the vehicle, and outputs a detection signal to the controller 70. The vehicle speed sensor 74 detects the traveling speed of the vehicle as the vehicle speed and outputs a detection signal to the controller 70. The lateral acceleration sensor 75 detects, for example, a lateral acceleration (lateral G) that acts during a turning operation of the vehicle, and outputs a detection signal to the controller 70. The lateral acceleration (lateral G) of the vehicle can also be obtained by calculation based on detection signals from the steering angle sensor 73, the vehicle speed sensor 74, and the like.

  The suspension device according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  Here, the hydraulic cylinders 1 to 4 are attached between the respective wheels of the vehicle and the vehicle body (that is, between the sprung and unsprung). When vibration occurs in the vehicle, the hydraulic cylinders 1 to 4 control the flow of pressure oil (hydraulic fluid) with respect to the stroke of the piston rod 7, for example, according to an external command from the controller 70, for example, a damping force adjustment mechanism The damping force is variably adjusted by 11, 13, 17, and 19 to increase or decrease.

  Among these, the first damping force adjusting mechanism 11 is an annular shape from the lower chamber B to the oil chamber C of the valve housing 41 when the piston 6 slides and displaces downward in the cylinder 5 in the extension stroke of the piston rod 7. A resistance force is applied to the hydraulic oil (pressure oil) flowing out through the oil passages 31 and 33 and the like, and an expansion-side damping force is generated with characteristics according to an external command (control command) from the controller 70. . Since the other damping force adjustment mechanisms 13, 17, and 19 operate in the same manner, the first damping force adjustment mechanism 11 will be described as a representative.

  That is, in the extension side damping force generator 53 of the first damping force adjusting mechanism 11, the damping force valve 55 is normally seated on the annular valve seat 43 </ b> D of the piston 43, and the pressure oil from the oil chamber C passes through the first passage ( For example, the flow to the oil chamber D through the oil passage 43B) of the piston 43 is blocked. However, even when the damping force valve 55 is closed, on the side of the second passage (for example, the inner passage 44F of the cylindrical rod 44, the passages 63B and 63C of the movable valve seat 63, the valve chamber E), the magnetic force from the solenoid 58 is used. By driving the poppet valve body 65 in the valve opening direction together with the operation pin 64, the valve chamber E of the movable valve seat 63 can be opened with a lift amount (opening) proportional to the energization amount.

  As described above, the solenoid 58 opens the poppet valve body 65 at an opening degree corresponding to the control command from the controller 70, so that on the second passage side, between the passages 63B and 63C of the movable valve seat 63, that is, The pressure in the valve chamber E that allows communication between the inner passage 44F of the cylindrical rod 44 and the oil passage 44D and the annular recess 54A of the valve seat member 54 can be variably adjusted. Therefore, the poppet valve element 65 is caused by the pressure oil flowing out from the annular recess 54A of the valve seat member 54 to the outer oil chamber D (connection pipe line 9) through the check disc valve 56 (including the orifice 56A). The extension-side damping force adjusted according to the opening degree (that is, the control command from the controller 70) can be generated.

  In addition, even on the side of the oil passage 43B (first passage) of the piston 43, when the pressure from the oil chamber C (pressure in the annular recess 43C) increases to a predetermined valve opening set pressure, the damping force valve 55 is The valve is opened away from the seat 43D. That is, a resistance force is applied to the pressure oil flowing from the oil chamber C of the valve housing 41 to the oil chamber D via the first passage (the oil passages 43B of the piston 43 and the annular recess 43C) by the damping force valve 55. The damping force on the extension side is generated.

  On the other hand, in the contraction stroke of the piston rod 7, the piston 6 slides upward in the cylinder 5, so that the lower chamber B in the cylinder 5 is operated from the oil chamber D (connection line 9) side of the valve housing 41. Oil (pressure oil) is supplied through the contraction side damping force generator 47. The compression-side damping force generator 47 applies resistance to the pressure oil flowing from the oil chamber D of the valve housing 41 to the oil chamber C via the oil passages 43A and the annular recesses 43E of the piston 43. The contraction-side damping force can be generated with characteristics according to the control command.

  That is, the compression-side damping force generator 47 of the first damping force adjustment mechanism 11 variably adjusts the valve opening pressure of the damping force valve 49 according to the pressure in the back pressure chamber 51. The back pressure chamber 51 provided between the pilot case 48 and the damping force valve 49 of the compression side damping force generating portion 47 is a valve seat member via the concave groove 44E of the cylindrical rod 44 and the oil guiding passages 52 and 57. 54 communicates with the annular recess 54A. Pressure oil from the outer oil chamber D (connection pipe line 9) flows into the annular recess 54A through the orifice 56A of the check disc valve 56 as a pilot pressure.

  This pilot pressure (pressure in the annular recess 54A) is placed in a pressure state equal to that in the valve chamber E of the movable valve seat 63 via the oil passage 44D of the cylindrical rod 44, and the like, for example, an external command ( By driving the solenoid 58 and the poppet valve body 65 with a control command), the pressure is variably adjusted in the same manner as the pressure in the valve chamber E. For this reason, the valve opening pressure of the damping force valve 49 is variably set according to the pilot pressure (back pressure) in the back pressure chamber 51, and the damping force during the contraction stroke of the piston rod 7 can be variably adjusted. Thus, the compression force damping valve 49 on the contraction side can variably set the pressure in the back pressure chamber 51 (the back pressure of the damping force valve 49) by the control command from the controller 70 (the magnetic force of the solenoid 58). The generated damping force can be variably adjusted.

  Thus, according to the present embodiment, the left hydraulic cylinder 1 on the front wheel side is provided with the first fixed valve 10 at the connection site between the upper chamber A and the first connection pipe 8, and the lower chamber B and the second hydraulic cylinder 1. The connecting portion with the connecting pipe 9 is variably adjusted with the damping force of the pressure oil flowing out from the lower chamber B toward the second connecting pipe 9, and is connected to the lower chamber from the second connecting pipe 9. A first damping force adjustment mechanism 11 configured as a bidirectional control valve (see FIGS. 2 and 3) that variably adjusts the damping force of the pressure oil flowing toward B is provided. The first fixed valve 10 includes a damping valve and a check valve 10A that attenuates the flow from the upper chamber A without electronically controlling the pressure oil flowing out from the upper chamber A toward the first connecting pipe 8 (see FIG. 2).

  Further, the right hydraulic cylinder 2 on the front wheel side is provided with a second fixed valve 12 at a connection portion between the upper chamber A and the second connection pipe 9, and the connection between the lower chamber B and the first connection pipe 8 is provided. The part is provided with a second damping force adjusting mechanism 13 configured as a bidirectional control valve that variably adjusts the damping force of the pressure oil. Further, the left and right hydraulic cylinders 3 and 4 on the rear wheel side also have the first and second fixed valves 16 and 18 and the first and second damping force adjustment mechanisms 17 and 19, as in the hydraulic cylinders 1 and 2. And are provided.

  For this reason, with respect to one hydraulic cylinder 1 to 4, without providing a damping force adjusting mechanism on both the upper chamber A side and the lower chamber B side, for example, a bidirectional control valve only on the lower chamber B side (see FIG. 2), the damping force can be adjusted simply by providing the damping force adjusting mechanism 11, 13, 17, 19 and the number of complicated control valves can be reduced, and the overall cost of the shim tem can be reduced. Weight reduction can be achieved.

  The bidirectional control valve used for the damping force adjusting mechanisms 11, 13, 17, and 19 has a complicated valve structure such as the contraction side and extension side damping force generation units 47 and 53 shown in FIGS. Since the two solenoids 58 can adjust and control the bi-directional damping force on the contraction side and the expansion side, the number of damping force adjusting mechanisms 11, 13, 17, and 19 can be reduced, and the overall structure can be simplified. This makes it possible to achieve both vehicle handling stability and riding comfort.

  Moreover, in this embodiment, by reducing the number of solenoids 58, the system / control logic can be simplified, and the load on the controller 70 (ECU) is also reduced. Furthermore, the number of electrical parts such as harnesses and control valves can be reduced, so that the workability during assembly can be improved and the failure of the electrical system can be prevented.

  Here, FIG. 6 shows test data (damping force characteristics) when the hydraulic cylinders 1 to 4 are used alone. For example, the damping force when the damping force (axial force) of the hydraulic cylinders 1 to 4 is measured by opening the bridge valves 21 and 23 in FIG. It becomes a characteristic.

  In this case, in the present embodiment, the bidirectional control valves used in the damping force adjusting mechanisms 11, 13, 17, 19 are, for example, the contraction side and extension side damping force generation units 47, 53 shown in FIGS. The number of damping force adjusting mechanisms 11, 13, 17, and 19 is reduced to half that of the comparative example. In contrast, in the comparative example, two current uniflow (one-way) control valves are provided independently on the upper chamber A side and the lower chamber B side with respect to one hydraulic cylinder.

  Characteristic lines 76 and 77 in FIG. 6 indicate the damping force characteristic in the extension stroke of the piston rod 7, the characteristic line 76 is a case where the damping force is a hard characteristic, and the characteristic line 77 is a characteristic where the damping force is a soft characteristic. This is the case. The damping force characteristics (characteristic lines 76 and 77) in the extension stroke are not substantially different between the case where the present embodiment is applied and the case of the comparative example.

  A characteristic line 78 in FIG. 6 is a case where the damping force characteristic in the contraction stroke of the piston rod 7 is a soft characteristic. The soft damping force characteristic (characteristic line 78) in the contraction process is not substantially different between the present embodiment and the comparative example. A characteristic line 79 in FIG. 6 shows a comparative example in which the damping force characteristic in the contraction stroke of the piston rod 7 is a hard characteristic, and a characteristic line 80 indicates the damping force characteristic in the contraction stroke in the present embodiment. This shows the case of hard characteristics.

  In the present embodiment in which one bidirectional control valve is provided, the elongation-side characteristics (characteristic lines 76 and 77) can be obtained as the same performance as the comparative example. However, the hard characteristic (characteristic line 80) on the contraction side cannot be increased as in the comparative example (characteristic line 79). However, by increasing the system pressure (encapsulation pressure), it is possible to increase the shrinkage-side hard characteristics to some extent.

  However, considering the influence on the control of the vehicle behavior, the hard characteristic (characteristic line 80) on the contraction side is capable of vehicle motion control that can be sufficiently experienced even with the hard characteristic along the characteristic line 80, for example. It has been confirmed by the test by. Therefore, if it can be confirmed that the necessary vehicle motion control can be performed even if the hard characteristics on the contraction side are as low as the characteristic line 80, it is possible to achieve a merit (sufficiently) that can simplify the system, save space, and reduce the cost. Product value).

  The suspension device according to the present embodiment, which is configured as described above, can maintain high roll rigidity and suppress sprung vibration due to roll resonance when traveling on rough roads. Improvements can be made possible. In particular, for one hydraulic cylinder 1 to 4, a damping force composed of a bidirectional control valve is provided only on the lower chamber B side without providing a damping force adjusting mechanism on both the upper chamber A side and the lower chamber B side. The damping force can be adjusted simply by providing the adjusting mechanisms 11, 13, 17, and 19. The number of complicated control valves can be reduced, and the cost and weight of the entire shim tem can be reduced.

  In the above embodiment, for example, the first damping force adjusting mechanism 11 is configured to include the contraction-side damping force generation unit 47 including the back pressure chamber 51 and the expansion-side damping force generation unit 53. And explained. However, the present invention is not limited to this. For example, if the generated damping force on the expansion side and the contraction side can be variably adjusted by electronic control, the configuration of the first damping force adjustment mechanism can be changed as appropriate. Good. This also applies to the second damping force adjustment mechanism.

  In the above embodiment, the pair of left and right hydraulic cylinders 1 and 2 interposed between the left and right wheels and the vehicle body are crossed by the first and second connecting pipes 8 and 9. As an example, the case of connecting with is described. However, the present invention is not limited to this. For example, in a two-wheeled vehicle, a pair of front and rear hydraulic (hydraulic) cylinders interposed between the front and rear wheels and the vehicle body are provided as first, You may comprise by connecting by a 2nd connection pipe line.

  Further, in the above-described embodiment, the case where the piston rod 7 protrudes downward from the cylinder 5 of the hydraulic cylinders 1 to 4 has been described as an example. However, the present invention is not limited to this. For example, the piston rod of each hydraulic cylinder may be configured to protrude upward from the cylinder.

  Next, as a suspension device included in the above-described embodiment, for example, the following modes can be considered.

  As a first aspect of the suspension device, a pair of hydraulic pressures are interposed between the left, right or front and rear wheels and the vehicle body, and the inside of the cylinder is divided into an upper chamber and a lower chamber by a piston. Between the cylinder and the pair of hydraulic cylinders, an upper chamber of one hydraulic cylinder communicates with a lower chamber of the other hydraulic cylinder, and an upper chamber of the other hydraulic cylinder is a lower portion of the one hydraulic cylinder. A first and second connecting pipes connected by a cross so as to communicate with the chamber; a first damping force adjusting mechanism that is provided in the one hydraulic cylinder and is capable of adjusting a damping force; and the other A second damping force adjusting mechanism provided in the hydraulic cylinder and capable of adjusting a damping force, wherein the first damping force adjusting mechanism is provided to communicate with the lower chamber of the one hydraulic cylinder; A structure that can adjust the damping force in both the expansion and contraction strokes. And, the second damping force adjusting mechanism, so provided that the communication with the lower chamber of the other hydraulic cylinder, any expansion or contraction stroke is characterized by the adjustable damping force configuration.

  As a second aspect of the suspension device, in the first aspect, the first damping force adjusting mechanism is configured to flow in and out between a lower chamber of the one hydraulic cylinder and the second connecting pipe. And a second damping force adjusting mechanism flows between the lower chamber of the other hydraulic cylinder and the first connection pipe. The hydraulic fluid to be discharged is configured to generate a damping force that increases or decreases in accordance with an external command.

  As a third aspect of the suspension apparatus, in the first or second aspect, the one hydraulic cylinder is provided with a first fixed valve at a position communicating with the upper chamber, and the first fixed valve Is configured to generate a damping force corresponding to the flow rate of the hydraulic fluid flowing out from the upper chamber toward the first connection pipe, and the other hydraulic cylinder is in a position communicating with the upper chamber. A second fixed valve is provided, and the second fixed valve is configured to generate a damping force corresponding to a flow rate in the hydraulic fluid flowing out from the upper chamber toward the second connection pipe line. Yes.

1, 2, 3, 4 Hydraulic cylinder (hydraulic cylinder)
DESCRIPTION OF SYMBOLS 5 Cylinder 6 Piston 7 Piston rod 8,14 1st connection pipe line 9,15 2nd connection pipe line 10,16 1st fixed valve 11,17 1st damping force adjustment mechanism 12,18 2nd fixed valve 13, 19 Second damping force adjusting mechanism 21, 23 Bridge valve 28 Rod guide 31, 33 Oil passage 41 Valve housing 43 Piston 43A, 43B Oil passage (first passage)
44D Oil passage (second passage)
44F Inner passage (second passage)
47, 53 Damping force generator 58 Solenoid 60 Coil 61 Stator core 62 Movable element 65 Poppet valve element A Upper chamber B Lower chamber C, D Oil chamber E Valve chamber

Claims (3)

A pair of hydraulic cylinders interposed between the left, right or front and rear wheels and the vehicle body, each of which is defined in an upper chamber and a lower chamber by a piston;
Between the pair of hydraulic cylinders, the upper chamber of one hydraulic cylinder communicates with the lower chamber of the other hydraulic cylinder, and the upper chamber of the other hydraulic cylinder communicates with the lower chamber of the one hydraulic cylinder. First and second connecting pipes connected by a cross as shown in FIG.
A first damping force adjusting mechanism provided on the one hydraulic cylinder and capable of adjusting a damping force;
A second damping force adjusting mechanism provided in the other hydraulic cylinder and capable of adjusting a damping force;
With
The first damping force adjusting mechanism is provided so as to communicate with the lower chamber of the one hydraulic cylinder, and is configured to be able to adjust the damping force in both expansion and contraction strokes.
The suspension device according to claim 1, wherein the second damping force adjusting mechanism is provided so as to communicate with the lower chamber of the other hydraulic cylinder, and the damping force can be adjusted in any of expansion and contraction strokes. The first damping force adjusting mechanism generates a damping force that increases or decreases in response to an external command to the hydraulic fluid that flows in and out between the lower chamber of the one hydraulic cylinder and the second connection pipe. age,
The second damping force adjusting mechanism generates a damping force that increases or decreases in response to an external command to the hydraulic fluid that flows in and out between the lower chamber of the other hydraulic cylinder and the first connection pipe. The suspension device according to claim 1, wherein: The one hydraulic cylinder is provided with a first fixed valve at a position communicating with the upper chamber, and the first fixed valve flows out of the upper chamber toward the first connection pipe. To generate a damping force according to the flow rate,
The other hydraulic cylinder is provided with a second fixed valve at a position communicating with the upper chamber, and the second fixed valve is discharged from the upper chamber toward the second connection pipe. The suspension device according to claim 1, wherein a damping force corresponding to the flow rate is generated.

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