JP2007223572A - Damper and motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy performance of putting a foot on the ground in a motorcycle with light weight and inexpensive cost. <P>SOLUTION: The damper D is applied to a rear wheel side suspension of the motorcycle 1. The damper D is equipped with a cylinder 10 which is connected to a vehicle body 2 of the motorcycle 1 and one side of a swing arm 3 rockably mounted to the vehicle body 2, a piston 11 which is movably inserted in the cylinder 10 and partitions the inside of the cylinder 10 into two pressure chambers R1, R2, a piston rod 11 which is connected to the piston 11, and connected to the vehicle body 2 and the other side of the swing arm, a reservoir R communicated to the one side of the pressure chamber R2, and a valve 13 which can switch between shut-off of flow of a fluid from at least reservoir R toward the one side pressure chamber R2 and communication of the reservoir R with one side pressure chamber R1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shock absorber and a motorcycle equipped with the shock absorber.

  Conventionally, in the suspension on the rear wheel side of a motorcycle, the vehicle body, a swing arm that is slidably mounted on the vehicle body, a shock absorber interposed between the vehicle body and the swing arm, the vehicle body and the rear wheel A suspension spring interposed in parallel with the shock absorber is provided between the suspension and the side suspension.

  The shock absorber absorbs and attenuates vibrations input from the road surface during traveling of the motorcycle and relaxes propagation of the vibrations to the vehicle body with a suspension spring so as to satisfy the riding comfort in the vehicle.

  As described above, motorcycles have improved riding comfort due to the suspension on the rear wheel side, and are particularly suitable for off-road motorcycles (hereinafter referred to as “off-road vehicles”) called motocrossers. Therefore, when driving on rough terrain, there are many opportunities to receive a large force from the road surface, so the minimum ground clearance is set from the viewpoint of running performance and large input reduction, and the suspension stroke length is set larger than that of vehicles for other applications. Will do.

  Then, since the minimum ground clearance and the stroke length are set large in the off-road vehicle, the vehicle height is inevitably high, and therefore, the foot contact property, which is the ground contact property when riding, tends to deteriorate.

  In order to improve this foot-holding property, a so-called meat removal method for removing the cushion member of the seat has been performed by the user of the motorcycle, but when such a method is adopted, the riding comfort deteriorates at the same time. This is not preferable because the distance between the seat height and the step of the motorcycle is shortened and the user is forced to take an unreasonable riding posture.

Therefore, in order to solve the above problem, a vehicle height adjusting device capable of narrowing the distance between the vehicle body and the axle before and after the motorcycle has been proposed. According to this vehicle height adjusting device, The vehicle height is adjusted by adjusting the distance by extending and contracting an actuator including a motor and a feed screw mechanism (see, for example, Patent Document 1).
Japanese Unexamined Patent Publication No. 2004-224111 (FIGS. 1 and 3)

  The above-described vehicle height adjusting device is useful in terms of improving the stepping performance of a motorcycle with a high vehicle height, such as an off-road vehicle, but even in off-road vehicles, particularly when it is intended for racing. This is not preferable because the weight of an actuator or the like increases and the vehicle weight increases.

  Furthermore, since both actuators are driven by a motor, they are expensive and disadvantageous in terms of economy.

  Accordingly, the present invention has been developed to improve the above-described problems, and an object of the present invention is to satisfy the footing property of a motorcycle at a light weight and low cost.

  In order to achieve the above-described object, a shock absorber according to the present invention includes a cylinder connected to one of a motorcycle body and a swing arm slidably attached to the motorcycle body, and a movably inserted cylinder. A piston that divides the inside of the cylinder into two pressure chambers; a piston rod that is coupled to the piston and coupled to the other of the vehicle body and the swing arm; a reservoir that communicates with one of the pressure chambers; and at least one from the reservoir And a valve capable of switching the flow of the fluid toward the pressure chamber and switching the communication between the reservoir and one of the pressure chambers.

  In order to achieve the above-described object, a motorcycle according to the present invention includes a vehicle body, a swing arm that is slidably attached to the vehicle body, and a shock absorber interposed between the vehicle body and a rear wheel side suspension. The shock absorber includes a cylinder, a piston that is movably inserted into the cylinder and divides the cylinder into two pressure chambers, a piston rod connected to the piston, and one of the pressure chambers And a valve capable of switching off the flow of fluid from the reservoir to the one pressure chamber and switching the communication between the reservoir and the one pressure chamber.

  According to the present invention, the vehicle height can be kept low by adding a valve to the shock absorber without requiring a large-scale device such as a conventional vehicle height adjustment device, and the weight of the motorcycle is increased. Therefore, it is possible to satisfy the footing property in a motorcycle at a light weight and low cost.

  The present invention will be described below based on the illustrated embodiment. FIG. 1 is a diagram conceptually showing a motorcycle according to an embodiment. FIG. 2 is a side view of the suspension on the rear wheel side when the motorcycle according to the embodiment is at a normal height. FIG. 3 is a cross-sectional view of the shock absorber in one embodiment. FIG. 4 is a side view of the rear-wheel-side suspension in a state where the motorcycle height in the embodiment is lowered.

  As shown in FIG. 1, a motorcycle 1 according to an embodiment includes a vehicle body 2, a front wheel W1, a rear wheel W2, and a rear wheel W2 attached to the rear of the vehicle body 2 so as to be freely swingable in the vertical direction in the figure. A swing arm 3 that is rotatably held, a handle 4 that is slidably mounted in front of the vehicle body 2 in the horizontal direction in the figure, and a front fork 5 that is connected to the handle 4 and that rotatably holds the front wheel W1. And a shock absorber D interposed between the vehicle body 2 and the swing arm 3 and a suspension spring K also interposed between the vehicle body 2 and the swing arm 3 in parallel with the shock absorber D. It is configured.

  The motorcycle 1 can travel by driving the power of an engine 6 mounted on the vehicle body 2 to a rear wheel W2 via a chain, belt, or shaft (not shown) and driving the rear wheel W2 to rotate. It is like that.

  In the motorcycle 1, the rear wheel suspension is configured to include the swing arm 3, the shock absorber D, the suspension spring K, and the link mechanism L described above. In the case of the form, one end of the shock absorber D is connected to the swing arm 3 via the link mechanism L, and is configured as a bottom link type suspension. In this way, when the compression of the shock absorber D proceeds to a certain extent by interposing the link mechanism L, the lever ratio (the rear wheel axle displacement amount divided by the shock absorber D displacement amount) reaches the maximum compression state from there. ) Is gradually becoming smaller. Therefore, this suspension exhibits a progressive characteristic in which the spring reaction force gradually increases with respect to the displacement such that the rear-wheel axle approaches the vehicle body 2.

  Specifically, as shown in FIG. 2, the link mechanism L includes a sub arm 7 slidably attached to the lower side in FIG. 2 from the swing arm 3 of the vehicle body 2, and a flange 3 a provided below the swing arm 3. A triangular link member 8 that rotatably holds the tip of the sub-arm 7 and the tip of the piston rod 12 of the shock absorber D, and the length of the sub-arm 7 so as to realize the above-described progressive characteristics. The position of the rotation fulcrum of the sub arm 7, the swing arm 3 and the piston rod 12 held by the link member 8 and the distance between the rotation fulcrums are adjusted.

  On the other hand, as shown in FIGS. 2 and 3, the shock absorber D includes a cylinder 10, a piston 11 that is movably inserted into the cylinder 10 and divides the cylinder 10 into two pressure chambers R1 and R2, and a piston 11, a piston R 12 connected to one pressure chamber R 2, a flow of fluid from the reservoir R toward the one pressure chamber R 2, and a communication between the reservoir R and the one pressure chamber R 2. The pressure chambers R1 and R2 and the reservoir R are filled with hydraulic oil.

  1 and 2, the upper end of the cylinder 10 of the shock absorber D is rotatably connected to the vehicle body 2, and the lower end of the piston rod 12 is connected to the link member 8 so as to be rotatable. Thus, the shock absorber D is connected to the swing arm 3 through the link member 8, and the shock absorber D is interposed between the vehicle body 2 and the swing arm 3.

  Hereinafter, the shock absorber D will be described in detail. The piston 11 includes a passage 11a that connects the one pressure chamber R2 and the other pressure chamber R1, and a leaf valve, a throttle valve, and the like in the middle of the passage 11a. The damping force generating element 11b is provided. Of course, a plurality of passages 11a may be provided. In this case, a passage 11a through which the hydraulic oil passes only during the compression stroke of the shock absorber D and a passage 11a through which the hydraulic oil passes only during the extension stroke are provided. It may be.

  In addition, a tank 17 is provided outside the cylinder 10 via a joint portion 16, and a flexible bladder 18 is provided in the tank 17. It is partitioned into a reservoir R and an air chamber G. A gas having a predetermined atmospheric pressure is sealed in the air chamber G, and the air pressure in the air chamber G is applied to the pressure chambers R1 and R2 and the reservoir R in the cylinder 10.

  The reservoir R communicates with one pressure chamber R2 via a pipe line 16a provided in the joint portion 16 described above. Further, a damping force generating element 16b capable of adjusting the flow path resistance is provided in the middle of the pipe line 16a of the joint portion 16. The damping force generating element 16b can change the damping force generated by the shock absorber D by adjusting the flow path resistance, and various known configurations can be employed.

  Further, a valve 13 is provided in the middle of the pipe line 16a, in the present embodiment, in the middle of the pipe line 16a and closer to the reservoir R than the damping force generating element 16b. In the present embodiment, it is configured as an electromagnetic two-position switching valve, and includes a blocking position 14 for blocking the flow of fluid from the reservoir R to the one pressure chamber R2, a reservoir R, and one pressure chamber R2. And a solenoid 20 is provided at one end of the valve 13 and a spring 21 is provided at the other end. When the solenoid 20 is energized, the thrust of the solenoid 20 is a biasing force of the spring 21. When the valve 13 is maintained at the shut-off position 14 and the solenoid 20 is not energized, the valve 13 is connected to the communication position by the biasing force of the spring 21. It is adapted to be maintained at 15.

  As shown in FIG. 1, the power supply to the solenoid 20 is performed from a power source E provided in the motorcycle 1, but is provided in the middle of the power source E and the solenoid 20 and by a switch 9 attached to the handle 4. Switching between energization and non-energization can be performed. That is, the passenger of the motorcycle 1 can turn on and off the solenoid 20 by manually operating the switch 9, and the valve 13 is switched between the cutoff position 14 and the communication position 15 by operating the switch 9. It will be. The power source E may be a battery mounted on the motorcycle 1, or may be provided separately for energization of the solenoid 20, or when the ECU 1 is mounted on the motorcycle 1. The ECU may detect an ON signal by operating the switch 9 and cause the ECU to energize the solenoid 20 when the ON signal is detected.

  The shock absorber D configured as described above is configured such that when the valve 13 takes the communication position 15, that is, in a state where the reservoir R and one pressure chamber R2 are in communication with each other, Since the volume in the other pressure chamber R1 decreases, the hydraulic oil in the pressure chamber R1 passes through the passage 11a and moves into the one pressure chamber R2, and the piston rod 12 retreats from the cylinder 10 for the volume. Hydraulic oil is supplied from the reservoir R into the pressure chamber R2. The damping force generating element 11b mainly functions as a resistance against the above-described flow of hydraulic oil, causing a pressure difference between the pressure chamber R1 and the pressure chamber R2, and generating a damping force during the extension stroke.

  On the contrary, when the shock absorber D is compressed in a state where the reservoir R and the one pressure chamber R2 are in communication with each other, the volume in the one pressure chamber R2 decreases, so that the hydraulic oil in the pressure chamber R2 passes through the passage. While passing through 11 a and moving into the other pressure chamber R <b> 1, the volume of hydraulic oil into which the piston rod 12 enters the cylinder 10 moves from the pressure chamber R <b> 2 to the reservoir R. At this time, the damping force generating element 16b functions as a resistance of the hydraulic oil moving to the reservoir R and functions to further increase the pressure in the pressure chamber R2, and the damping force generating element 11b uses the pressure chamber R1 and the pressure chamber R2. A pressure difference is produced between the two and a damping force during the compression stroke is generated.

  That is, when the valve 13 takes the communication position 15, the shock absorber D exhibits a normal action, that is, an action that can be expanded and contracted and generates a damping force by the expansion and contraction.

  On the other hand, when the valve 13 takes the cutoff position 14, the shock absorber D is in an unextendable state.

  That is, when the shock absorber D is expanded and contracted, the piston rod 12 enters and exits the cylinder 10, and the volume of hydraulic oil that enters and exits becomes excessive and insufficient in the cylinder 10, and this excess and insufficient hydraulic oil is supplied by the reservoir R. Alternatively, if the valve 13 takes the shut-off position 14, only the supply of hydraulic oil from the reservoir R to the one pressure chamber R 2 is blocked and the piston rod 12 tries to withdraw from the cylinder 10. Since one minute of hydraulic oil is not supplied to the cylinder 10 from the reservoir R, one of the pressure chambers R2 has a negative pressure and the shock absorber D cannot expand. On the contrary, when the valve 13 takes the shut-off position 14, the movement of the hydraulic oil from one pressure chamber R2 to the reservoir R is permitted. Since the hydraulic oil moves from the cylinder 10 to the reservoir R, in this case, the shock absorber D can be compressed.

  Therefore, as described above, when the valve 13 takes the shut-off position 14, the shock absorber D is only allowed to be compressed and cannot be expanded, so that the shock absorber D can be freely expanded and contracted manually. It is possible to switch to a state in which extension is impossible.

  Since the shock absorber D is configured as described above, the switch 9 is operated to maintain the valve 13 at the shut-off position 14, and the vehicle body weight is balanced with the reaction force of the suspension spring K and the shock absorber D. When the vehicle body 2 of the motorcycle 1 is pushed downward from the normal vehicle height in the state (the state shown in FIG. 2), the shock absorber D is compressed and the compressed state (the state shown in FIG. 4) is obtained. Since the vehicle height on the rear wheel side of the vehicle body 2 is lowered, the suspension spring K is also maintained in a compressed state, and the vehicle body 2 is maintained at a vehicle height lower than the normal vehicle height.

  When it is desired to further reduce the vehicle height from the state where the vehicle height shown in FIG. 4 is lowered, the shock absorber D may be further compressed by pushing the vehicle body 2 downward.

  Thus, in the motorcycle 1 equipped with the above-described shock absorber D, the vehicle height can be lowered by the above-described operation, and the vehicle height can be kept low. The ride height can be improved by lowering the height of a motorcycle such as a car that has a high vehicle height.

  Then, with the vehicle height kept low, the occupant starts the engine 6 across the motorcycle 1 to start running, and then operates the switch 9 to switch the valve 13 to the communication position 15. The reservoir R and the pressure chamber R2 communicate with each other so that the shock absorber D can freely expand and contract, and the rod reaction force obtained by multiplying the area of the piston 11 by the area of the piston rod 12 multiplied by the pressure of the pressure chamber R2. In combination with the restoring force of the compressed suspension spring K, the shock absorber D and the suspension spring K are restored to the state before compression, and this time, the damper D exerts a damping force as usual, and in combination with the suspension spring K, the automatic The vibration of the vehicle body 2 of the two-wheeled vehicle 1 can be suppressed.

  That is, in the motorcycle 1 equipped with the shock absorber D according to the present embodiment, it is possible to keep the vehicle height on the rear wheel side low at the start when the footing becomes a problem. Therefore, even a short occupant does not impose a difficult starting work such as starting the engine 6 while standing the motorcycle 1 using a stand.

  Further, since the legging property is improved, the passenger can start the motorcycle 1 in a stable posture. In particular, in a motocross race, the motorcycle 1 is started in a stable posture as described above. In addition to being able to support the motorcycle 1, it is possible to support the motorcycle 1 so as to be substantially perpendicular to the ground by improving the legging property of the motorcycle 1. An early start dash is possible.

  Therefore, the vehicle height can be lowered by adding the valve 13 to the shock absorber D without requiring a large-scale device like the conventional vehicle height adjusting device, and compared with the conventional vehicle height adjusting device. Thus, the weight increase of the motorcycle 1 can be reduced, and it is inexpensive and advantageous in terms of economy. Therefore, it is possible to satisfy the footing property of the motorcycle 1 at a light weight and low cost.

  Furthermore, except for the start time when footing is required, the vehicle height returns to the original height by switching the valve 13 to the communication position 15, but the time required for the expansion of the shock absorber D is short. Therefore, the responsiveness when returning the vehicle height to the original normal vehicle height is improved, and the vehicle height is returned to a vehicle height sufficient for traveling on rough terrain, so that the running performance of the motorcycle 1 is not impaired.

  Furthermore, the valve 13 allows the hydraulic oil to flow from the one pressure chamber R2 to the reservoir R when the cut-off position 14 is adopted, so that the shock absorber D can be compressed but extended. This is a complicated vehicle in which the operation of switching the valve 13 and the operation of pushing down the vehicle body 2 must be performed simultaneously when lowering the vehicle height. It is freed from the high adjustment work, and the vehicle height adjustment work can be simplified by only pushing the vehicle body 2 downward.

  In addition, although the advantage which can simplify the above-mentioned vehicle height adjustment work is lost, you may make it comprise the valve 13 as an on-off valve which only opens and closes the pipe line 16a by operation of the switch 9. FIG.

  Further, the position of the valve 13 can be set in the middle of the pipe line 16a and closer to the pressure chamber R2 than the damping force generating element 16b. Even in such a case, the above-described effects can be obtained. is there.

  Further, in the above description, the valve 13 is switched by the solenoid 20, but this may be configured to be switched manually. Further, as described above, since the valve 13 is configured to take the communication position 15 in a state where the solenoid 20 is not energized, the shock absorber D can be used even if the energization to the solenoid 20 is interrupted. The normal function is exhibited and the vehicle height adjustment function cannot be exhibited, but a situation that impairs the riding comfort of the motorcycle 1 is avoided.

  In addition, as described above, the valve 13 is set so as to be switchable by manual operation. For example, a vehicle speed sensor is attached to the motorcycle 1, and the vehicle speed detected by the sensor exceeds a threshold value. The valve 13 can be automatically switched to the communication position 15. In this case as well, the effects of the present invention can be achieved.

  In the above-described embodiment, the rear wheel side suspension is configured as a bottom link type suspension, but may be a top link type suspension, or the link mechanism L may be eliminated and Even if the suspension is configured such that the shock absorber D is interposed between the vehicle body and the vehicle body, the operational effects of the present invention are not lost.

  Further, as the configuration of the shock absorber D, in addition to the reservoir R formed in the tank 17 separate from the cylinder 10, it may be configured as a double cylinder type in which the reservoir is formed on the outer periphery of the cylinder. The present invention can also be applied to a single cylinder type shock absorber in which a reservoir and an air chamber are formed in a cylinder.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

1 is a diagram conceptually showing a motorcycle in an embodiment. FIG. 1 is a side view of a suspension on a rear wheel side at a normal vehicle height of a motorcycle in an embodiment. It is sectional drawing of the buffer in one Embodiment. FIG. 3 is a side view of a rear wheel suspension in a state where the motorcycle height in the embodiment is lowered.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Car body 3 Swing arm 3a Flange 4 Handle 5 Front fork 6 Engine 7 Sub arm 8 Link member 9 Switch 10 Cylinder 11 Piston 12 Piston rod 13 Valve 11a Passage 11b, 16b Damping force generating element 14 Blocking position 15 Communication position 16 Joint Part 17 Tank 18 Bladder 20 Solenoid 21 Spring D Buffer E Power supply G Air chamber K Suspension spring L Link mechanism R Reservoir R1, R2 Pressure chamber W1 Front wheel W2 Rear wheel

Claims (4)

A cylinder connected to one of a motorcycle body and a swing arm attached slidably to the vehicle body, a piston that is movably inserted into the cylinder and divides the cylinder into two pressure chambers, and a piston A piston rod connected to the other of the vehicle body and the swing arm, a reservoir communicated with one of the pressure chambers, a block of a flow of fluid from at least the reservoir to the one pressure chamber, and a pressure of the reservoir and one of the reservoirs A shock absorber characterized by comprising a valve capable of switching communication between chambers. The shock absorber according to claim 1, wherein the valve can be switched between the shut-off and the communication by a manual operation. The shock absorber according to claim 1 or 2, wherein the valve is an electromagnetic switching valve that is switched between the shut-off and the communication by a solenoid and is set to be shut off when energized. In a motorcycle including a vehicle body, a swing arm attached to the vehicle body so as to be swingable, and a shock absorber interposed between the vehicle body and a rear wheel side suspension, the shock absorber moves into the cylinder and the cylinder. A piston that is freely inserted and divides the inside of the cylinder into two pressure chambers, a piston rod that is connected to the piston, a reservoir that communicates with one of the pressure chambers, and a fluid that is directed from at least the reservoir to one pressure chamber A motorcycle comprising: a valve capable of switching a flow shutoff and communication between a reservoir and one pressure chamber.

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