Suspension system

Abstract

To provide a suspension device in which an outer diameter of a piston is comparatively small and which enables an electric damper to be replaced with a hydraulic damper, with a comparatively simple configuration.SOLUTION: The suspension device comprises: a hydraulic damper 7 having a rod 11 with a valve 13 that is displaced between a first liquid chamber 4 and a second liquid chamber 5 to generate liquid pressure; and an electric damper 6 that makes an actuator electrically displace the rod 11, which further comprises a space 15, a space 16, a coil inner passage 24, a bypass passage chamber 31, a bypass hole 33 and a bypass passage chamber 35 which act as a communication passage through which the first liquid chamber 4 is communicated with the second liquid chamber 5, while detouring the valve 13, when activating the electric damper.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to a suspension device. [Background technology]

[0002] Patent Document 1 discloses that a hydraulic damper is housed inside an electromagnetic damper. Here, the piston of the hydraulic damper is provided with a fluid passage and a pin that is inserted through the fluid passage. In the normal stroke, the reduced diameter portion of the pin faces the fluid passage, forming a relatively large gap, so that the damping force of the hydraulic damper is reduced. In the end-side stroke region, the large diameter portion of the pin faces the fluid passage, so that the damping force of the hydraulic damper is increased. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-227927 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, the technology of Patent Document 1 uses the reduced diameter portion and the large diameter portion of the pin to adjust the electromagnetic damper and the hydraulic damper. However, this method has the disadvantage that the outer diameter of the piston becomes large, making the structure complicated. SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a suspension device that can switch between an electric damper and a hydraulic damper even when the outer diameter of the piston is relatively small and the structure is relatively simple. [Means for solving the problem]

[0005] The present invention provides a hydraulic damper having a rod equipped with a valve for generating hydraulic pressure by being displaced between a first liquid chamber and a second liquid chamber, and an electric damper for electrically displacing the rod by an actuator, the electric damper including a communication passage for bypassing the valve and communicating between the first liquid chamber and the second liquid chamber when the electric damper is operated. The electric damper includes a magnet and a coil, and the magnet has an internal flow passage that communicates the first liquid chamber and the second liquid chamber. It is characterized by the fact that Effect of the Invention

[0006] According to the present invention, it is possible to provide a suspension device that can switch between an electric damper and a hydraulic damper even though the outer diameter of the piston is relatively small and the structure is relatively simple. [Brief description of the drawings]

[0007] [Figure 1A] 1 is a cross-sectional view of a suspension device according to an embodiment of the present invention. [Figure 1B] FIG. 1B is an enlarged view of part A in FIG. 1A. [Diagram 2] FIG. 2 is an enlarged perspective view of a shutter member portion of the suspension device according to one embodiment of the present invention. [Figure 3A] FIG. 1C is a partially enlarged view of FIG. [Figure 3B] FIG. 3B is a diagram illustrating the maximum stroke of the electric damper in FIG. 3A. [Figure 4A] 1 is a conceptual diagram of a suspension device for explaining the operation of the suspension device according to an embodiment of the present invention; [Figure 4B] 1 is a conceptual diagram of a suspension device for explaining the operation of the suspension device according to an embodiment of the present invention; [Figure 4C] 1 is a conceptual diagram of a suspension device for explaining the operation of the suspension device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1A is a cross-sectional view of a suspension device according to one embodiment of the present invention. Fig. 1B is an enlarged view of part A in Fig. 1A. An inner cylinder 3 is housed in an outer housing 2 of the suspension device 1. Hereinafter, the right-hand tip side of the suspension device 1 in Fig. 1B may be referred to as the tip side. The left-hand side of the suspension device 1 in Fig. 1B may be referred to as the rear side.

[0009] The suspension device 1 includes a hydraulic damper 7. The hydraulic damper 7 is composed of a rod 11, a piston 12, valves 13 and 14, etc. The hydraulic damper 7 functions as a conventional suspension. That is, a rod 11 that is coaxial with the inner cylinder 3 is housed inside the inner cylinder 3. The rod 11 is movable within the inner cylinder 3 in the longitudinal direction of the inner cylinder 3 (left and right direction in FIG. 1B). A piston 12 is provided on the tip side (right side) of the rod 11 in the longitudinal direction. The outer circumferential surface of the piston 12 moves along the inner circumferential surface of the inner cylinder 3.

[0010] The piston 12 divides the inside of the inner cylinder 3 into a first liquid chamber 4 on the rear side of the piston 12 and a second liquid chamber 5 on the tip side of the piston 12. A cylindrical magnet 21 is provided in the piston 12, and a magnet internal flow path 22 that connects the first liquid chamber 4 and the second liquid chamber 5 is provided in the magnet 21. A valve 13 is provided at the front of the piston 12 in the magnet internal flow path 22. A valve 14 is provided at the front of the inner cylinder 3. The valve 14 can connect the inside of the inner cylinder 3 to a space 15 between the inner cylinder 3 and the outer housing 2. The space in the suspension device 1 is filled with a liquid such as oil. Therefore, by displacing the rod 11 between the first liquid chamber 4 and the second liquid chamber 5 with the valves 13 and 14 open, the liquid flows through the magnet internal flow path 22 and the field valves 13 and 14, the piston 12 moves, and the hydraulic damper 7 can generate hydraulic pressure.

[0011] The suspension device 1 also includes an electric damper 6 (electromagnetic damper). The electric damper 6 is composed of a magnet 21, a coil 23, and the like. The electric damper 6 functions as an electromagnetic suspension. That is, a cylindrical coil 23 (actuator) is provided between the outer housing 2 and the inner cylinder 3. By passing electricity through the coil 23, a magnetic field is generated, and this magnetic field acts on the magnet 21, so that the piston 12, and therefore the rod 11, can be moved in their axial directions. A space 16 is also provided between the outer housing 2 and the inner cylinder 3. An inner coil passage 24 is provided in the coil 23. The inner coil passage 24 connects the space 15 and the space 16.

[0012] A bypass passage chamber 31 is provided inside the space 16 and outside the inner cylinder 3. A bypass hole 33 that connects the first liquid chamber 4 and the bypass passage chamber 31 is provided on the rear side of the wall of the inner cylinder 3 that constitutes the bypass passage chamber 31. A bypass hole 34 that connects the space 16 and the bypass passage chamber 31 is provided on the tip side of the wall 32 of the bypass passage chamber 31 on the space 16 side. The first liquid chamber 4 and the space 16 can communicate with each other via the bypass passage chamber 31 and the bypass holes 33 and 34.

[0013] Similarly, a bypass passage chamber 35 is provided inside the space 15 and outside the inner cylinder 3. A bypass hole 36 that communicates between the space 15 and the bypass passage chamber 35 is provided on the rear side of a wall 37 of the bypass passage chamber 35 on the space 15 side. The tip side of the bypass passage chamber 35 is open, and the second liquid chamber 5 and the space 15 can communicate with each other via the bypass passage chamber 35 and the bypass hole 36. In this manner, the bypass passage chamber 31, the space 16, the coil internal passage 24, the space 15, the bypass passage chamber 35, etc. form a communication passage that bypasses the valve 13 and communicates between the first liquid chamber 4 and the second liquid chamber 5.

[0014] A circular shutter member 41 is slidably wound around the bypass hole 34 of the inner tube 3. FIG. 2 is an enlarged perspective view of the shutter member 41. A plurality of punch holes 42 are formed in the circular part of the shutter member 41. A brim-shaped member 41a protrudes outward from the circular shutter member 41. Returning to FIG. 1B, the shutter member 41 is biased rearward in the axial direction of the inner tube 3 by a spring 49. In this state, the shutter member 41 closes the bypass hole 34. The shutter member 41 is made of metal, and moves against the biasing force of the spring 49 by a magnetic field generated by energizing the coil 23. As a result, the bypass hole 34 and the punch hole 42 are aligned, and the bypass hole 34 is opened.

[0015] In FIG. 1B, an annular shutter member 46 is slidably wrapped around the position of the bypass hole 36 of the inner tube 3. The configuration of the shutter member 46 is the same as that of the shutter member 41. A plurality of punch holes 47 are formed in the annular portion of the shutter member 46. The shutter member 46 is biased toward the tip side in the axial direction of the inner tube 3 by a spring 48. In this state, the shutter member 46 closes the bypass hole 36. The shutter member 46 is made of metal, and moves against the biasing force of the spring 48 due to the action of a magnetic field generated by passing electricity through the coil 23. As a result, the positions of the bypass hole 36 and the punch holes 47 match, and the bypass hole 36 opens.

[0016] By opening the bypass holes 34, 36, the bypass passage chamber 31, the space 16, the coil inner passage 24, the space 15, and the bypass passage chamber 35 become a communication passage that bypasses the valve 13 and communicates between the first liquid chamber 4 and the second liquid chamber 5. The shutter members 41, 46 become opening and closing parts that open and close the communication passage in this case. As is clear from the above description, the electric damper 6 is an electromagnetic damper that uses a magnetic force generated by a linear motor that is composed of the magnet 21, the coil 23, and the like.

[0017] The shutter members 41 and 46, which serve as the opening and closing parts, use a magnetic force generated by the linear motor when opening. Fig. 3A is a partially enlarged view of Fig. 1B. Fig. 3B is a view showing the electric damper 6 at its maximum stroke in Fig. 3A. The bypass hole 33 between the first liquid chamber 4 and the bypass passage chamber 31 is provided at a position where it is not blocked by the magnet 21 at the maximum stroke of the electric damper 6 as shown in Fig. 3B.

[0018] Next, the operation of this embodiment will be described. 4A to 4C are conceptual diagrams of the suspension device 1 for explaining the operation of the suspension device 1. When the vehicle is normally traveling, the suspension device 1 uses an electric damper 6 as shown in FIG. 4A. In this case, the shutter members 41, 46 are open. Therefore, each chamber is connected via the above-mentioned communication passage, and the liquid can move inside the suspension device 1 as shown by the arrows in FIG. 4A, and the liquid does not pass through the valves 13, 14. Therefore, no liquid pressure is generated, and no damping by the liquid occurs. The electric damper 6 controls the piston 12 by electromagnetic force to generate a damping force against the vibration of the vehicle.

[0019] 4B and 4C are conceptual diagrams of the suspension device 1 using a hydraulic damper. FIG. 4B shows the rod 11 contracting (entering the suspension device 1), and FIG. 4C shows the rod 11 expanding (coming out of the suspension device 1). As described above, the electric damper 6 is used during normal vehicle running, but when the control of the electric damper 6 is OFF or when there is a failure, the hydraulic damper 7 is used. That is, when the control of the electric damper 6 is OFF or when there is a failure, the current to the coil 23 is stopped, and the shutter members 41, 46 are closed. Then, the liquid flow as shown by the arrows in FIG. 4A disappears. Therefore, the hydraulic damper 7 generates a damping force against the vibration of the vehicle at the valves 13, 14, similar to a normal twin-tube damper.

[0020] Therefore, when a system failure or the like occurs in the electric damper 6 (when any current cannot be supplied to the coil 23), the electric damper 6 can quickly switch to the hydraulic damper 7, so that even immediately after a system failure occurs, there is no shortage of damping and the vehicle behavior can be stabilized. Moreover, since only a communication passage through which liquid flows is formed as shown in FIG. 4A, the outer diameter of the piston 12 is relatively small, making it possible to provide a suspension device 1 with a relatively simple structure.

[0021] In addition, the communication passage is provided with shutter members 41, 46 as an opening and closing section. Therefore, when a system failure or the like occurs in the electric damper 6, it is possible to quickly switch to the hydraulic damper 7, so that even immediately after the occurrence of a system failure, damping is not insufficient and vehicle behavior can be stabilized. The electric damper 6 is an electromagnetic damper that uses the magnetic force generated by the linear motor, and therefore the electric damper 6 can be driven smoothly.

[0022] The shutter members 41 and 46 as the opening and closing parts are driven by the magnetic force generated by the linear motor. Therefore, when a system failure occurs in the electric damper 6, it can be reliably switched to the hydraulic damper 7. 1B, the bypass hole 33 is provided at a position where it is not blocked by the magnet 21 when the electric damper 6 is at its maximum stroke. Therefore, the communication passage is not blocked when the electric damper 6 is driven, so that the electric damper 6 can be driven smoothly at its maximum stroke. [Explanation of symbols]

[0023] 1 Suspension device 4 First Liquid Chamber 5 Second Liquid Chamber 6 Electric damper 7 Hydraulic Damper 11 Rod 12 Piston 13 Valve 14 Valve 15 Space (communication path) 16 Space (communication path) 21 Magnet (linear motor) 23 Coils (actuators, linear motors) 24 Coil internal passage (connecting passage) 31 Bypass passage room (connecting passage) 33 Bypass hole (connection passage) 35 Bypass passage room (connecting passage) 41 Shutter member (opening / closing part) 46 Shutter member (opening / closing part)

Claims

1. a hydraulic damper having a rod with a valve for generating hydraulic pressure by being displaced between a first fluid chamber and a second fluid chamber; an electric damper that electrically displaces the rod by an actuator; a communication passage that bypasses the valve and communicates between the first liquid chamber and the second liquid chamber when the electric damper is activated, The electric damper includes a magnet and a coil. a magnet having a flow passage formed therein, the flow passage connecting the first liquid chamber and the second liquid chamber;

2. 2. The suspension device according to claim 1, wherein the communication passage is provided with an opening / closing portion for opening and closing the communication passage.

3. 3. The suspension device according to claim 1, wherein the electric damper is an electromagnetic damper that uses a magnetic force generated by a linear motor.

4. 3. The suspension device according to claim 2, wherein the opening and closing portion uses a magnetic force generated by a linear motor.

5. 5. A suspension device according to claim 1, wherein the hole between the first fluid chamber and the communicating passage is provided at a position where it is not blocked by a magnet of the electric damper when the electric damper is at its maximum stroke.

6. a hydraulic damper having a rod with a valve for generating hydraulic pressure by being displaced between a first fluid chamber and a second fluid chamber; an electric damper that electrically displaces the rod by an actuator; a communication passage that bypasses the valve and communicates between the first liquid chamber and the second liquid chamber when the electric damper is activated, The electric damper includes a magnet and a coil. The coil is provided between an outer housing and an inner cylinder, a coil having an internal passage that constitutes a part of the communication passage, the coil being formed with the internal passage;

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