stabilizer device

Abstract

To provide a stabilizer device which ensures rigidity and improves ground contact when traveling on rough roads. [Solution] A stabilizer device comprising a stabilizer arm that connects left and right knuckles connected to a lower arm that supports the axles of a vehicle and suppresses the difference in displacement between the left and right axles through torsional rigidity, and stabilizer links 20 that are respectively interposed between both ends of the stabilizer arm and the knuckles, wherein the stabilizer link 20 comprises a cylinder 21, a piston 22, and a spring 24 that urges the stabilizer link 20 in a contracting direction, and is installed with a preload applied so that it will extend when a load acts on the stabilizer link 20 in the extension direction beyond a predetermined amount, and has non-linear characteristics.

Description

[Technical Field]

[0001] The present invention relates to a stabilizer device provided in a vehicle. [Background technology]

[0002] Many vehicles employ stabilizer devices to enhance roll rigidity. The stabilizer device includes, for example, a stabilizer bar, which is a torsion spring provided between left and right suspension arms that support the wheels, and left and right stabilizer links that connect both ends of the stabilizer bar to the left and right suspension arms, respectively. For example, the stabilizer link (connecting mechanism) described in Patent Document 1 comprises a cylindrical body, a piston that slides within the cylindrical body, and a spring that biases the piston, with a suspension arm connected to the cylindrical body and a compression spring provided between the piston and the end of the stabilizer bar.

[0003] Furthermore, Patent Document 1 is equipped with a device that applies hydraulic pressure inside the cylindrical body of the stabilizer link, and is configured to change the initial deflection of the spring by controlling the hydraulic pressure, thereby making it possible to arbitrarily change the torsional rigidity of the stabilizer bar, i.e., the roll rigidity of the vehicle caused by the stabilizer device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-113913 Summary of the Invention [Problem to be solved by the invention]

[0005] The stabilizer device in Patent Document 1 is configured to apply a spring force when the axle moves upward over a bump, but when the axle moves downward over a rebound, the spring does not work and the movement in the extension direction is restricted by the hydraulic pressure inside the cylinder. Therefore, when the axle moves downward over a rebound, the axle does not lower easily, which causes a problem of reduced wheel (tire) contact with the ground when driving on rough roads (off-road).

[0006] Although it is possible to allow extension of the stabilizer link by controlling the hydraulic pressure inside the cylinder using the hydraulic control device inside the cylinder as described in Patent Document 1, there is a problem in that the adoption of a hydraulic control device increases the cost of parts. The present invention has been made to solve such problems, and aims to provide a stabilizer device for a vehicle that increases rigidity to ensure steering stability and has excellent ground contact when driving on rough roads. [Means for solving the problem]

[0007] In order to achieve the above object, the stabilizer device of the present invention is a stabilizer device comprising: a stabilizer arm that connects support parts that support left and right axles of a vehicle and suppresses the difference in displacement between the left and right axles by torsional rigidity; and stabilizer links that are respectively interposed between both end parts of the stabilizer arm and the support parts, wherein the stabilizer links are extendable and have biasing means that bias the stabilizer links in an extending or contracting direction, and the biasing means is installed with a preload applied so that the stabilizer links expand and contract in a direction that reduces the rigidity of the stabilizer device when a load acts on the stabilizer links in the extending or contracting direction exceeding a predetermined amount, and the stabilizer links have non-linear characteristics. [Effects of the Invention]

[0008] According to the stabilizer device of the present invention, a preload is applied to the biasing means of the stabilizer link, thereby increasing the rigidity of the stabilizer device when an expansion load of a predetermined amount or less acts on the stabilizer link, and decreasing the rigidity of the stabilizer device when an expansion load exceeding the predetermined amount acts on the stabilizer link. Therefore, when the relative displacement between the left and right axles is relatively small, such as when cornering on a paved road, the rigidity of the stabilizer device can be increased, suppressing vehicle roll and improving handling stability. Also, when the relative displacement between the left and right axles is relatively large, such as when driving on rough roads, the rigidity of the stabilizer device can be reduced, increasing the relative displacement between the left and right axles and improving wheel contact with the ground. This improves off-road performance. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing the structure of a suspension device for a vehicle that employs a stabilizer device according to an embodiment of the present invention; [Figure 2] FIG. 1 is a perspective view of a stabilizer device according to an embodiment of the present invention. [Figure 3] 1 is a vertical cross-sectional view showing the structure of a stabilizer link according to a first embodiment of the present invention. [Figure 4] 4 is a graph showing the relationship between the displacement and the load of the stabilizer link in the first embodiment. [Figure 5] 4 is a graph showing the relationship between the relative displacement of the left and right wheels of a vehicle using a stabilizer device having the stabilizer link of the first embodiment and the rigidity of the stabilizer device. [Figure 6] FIG. 6 is a vertical cross-sectional view showing the structure of a stabilizer link according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a vertical cross-sectional view showing the structure of a stabilizer link according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing the structure of vehicle suspension devices 1 and 2 that employ a stabilizer device 10 according to an embodiment of the present invention. Fig. 2 is a perspective view of the stabilizer device 1 according to this embodiment. A stabilizer device 10 according to an embodiment of the present invention is a device that suppresses torsion by connecting support parts of axles in left and right suspension devices 1 and 2 of a vehicle. For example, as shown in FIG. 1, the device has a structure in which left and right knuckles 7 that connect upper arms 5 and lower arms 6 of left and right double wishbone suspension devices 1 and 2 are connected by stabilizer arms 11 that function as torsion springs. As shown in FIGS. 1 and 2, the stabilizer arm 11 is, for example, in the shape of a circular pipe, and is supported on the vehicle body at two locations, left and right, by folders 12 fixed to the vehicle body. Stabilizer links 20 are interposed on the left and right between the ends of the stabilizer arms 11 and the knuckles 7, respectively. As shown in Figure 3, the stabilizer link 20 includes a cylindrical cylinder 21, a piston 22 installed in the cylinder 21 so as to be slidable in the axial direction of the cylinder 21, a rod 23 having the piston 22 fixed to one end thereof, and a spring 24 provided in the cylinder 21 to bias the piston 22 against the cylinder 21.

[0011] The axes of the cylinder 21 and the rod 23 are aligned on the same line. The other end of the rod 23 protrudes from one end of the cylinder 21, and a joint 25 is provided at the protruding end for connection to the end of the stabilizer arm 11 and one of the knuckles 7. A joint 26 for connecting to the other of the end of the stabilizer arm 11 and the knuckle 7 is provided at the end of the cylinder 21 opposite to the protruding direction of the rod 23 .

[0012] The spring 24 biases the piston 22 toward the joint 26. That is, the spring 24 biases the stabilizer link 20 in the contracting direction. The movement of the piston 22 toward the joint 26, i.e., the movement of the stabilizer link 20 in the contracting direction, is restricted by an inner wall 27 on the joint 26 side of the cylinder 21. Furthermore, the movement of the piston 22 toward the joint 25, i.e., the movement of the stabilizer link 20 in the extending direction, is restricted by an inner wall 28 on the joint 25 side of the cylinder 21. This allows the stabilizer link 20 to expand and contract within a predetermined range.

[0013] Fig. 4 is a graph showing the relationship between the displacement (extension amount) of the stabilizer link 20 of the first embodiment and the load. Fig. 5 is a graph showing the relationship between the relative displacement of the left and right wheels of a vehicle using the stabilizer device 10 having the stabilizer link 20 of the first embodiment and the rigidity of the stabilizer device 10. Fig. 4 shows the relationship between the load acting on the rod 23 in the extension direction and the displacement in the extension direction, and the state in which the piston 22 is in contact with the inner wall 27 of the cylinder 21 is the displacement of 0.

[0014] As shown in Fig. 4, in this embodiment, when no load is applied to the stabilizer link 20, the biasing force of the spring 24 causes the piston 22 to contact the inner wall 27 of the cylinder 21, and the displacement is zero. When the load in the direction extending the stabilizer link 20 is equal to or less than the preload (predetermined amount a), which is the initial biasing force of the spring 24, the piston 22 hardly moves from the contact position with the inner wall 27, and the stabilizer link 20 hardly extends. When the load in the direction extending the stabilizer link 20 exceeds the preload of the spring 24 (exceeds the predetermined amount a), the stabilizer link 20 extends significantly in response to an increase in load. The stabilizer link 20 having such a spring 24 is set so that the relationship between the load and the amount of extension / contraction has nonlinear characteristics.

[0015] When the stabilizer arms 11 of the stabilizer device 10, which connects the support parts of the left and right axles, are twisted due to the displacement of the left and right wheels during a vehicle turn, the stabilizer link 20 on the inside of the turn receives a load in the direction of extension, and the stabilizer link 20 on the outside of the turn receives a load in the direction of contraction. However, when the vehicle is turning on a flat road, the relative displacement between the left and right wheels is smaller than when driving on a rough road.

[0016] Furthermore, the stabilizer device 10 using the stabilizer link 20 of this embodiment is preloaded in the contraction direction by the spring 24, so even if the stabilizer link 20 receives a load in the direction of extension, if the load is less than the biasing force of the spring 24, the stabilizer link 20 will not extend, twisting of the stabilizer arm 11 is suppressed, and the rigidity of the stabilizer device 10 as a whole is ensured.

[0017] Furthermore, if the stabilizer link 20 receives a load in a direction that causes it to expand greater than the biasing force of the spring 24, the stabilizer link 20 expands, causing the stabilizer arm 11 to twist more, and the rigidity of the stabilizer device 10 as a whole to decrease. Therefore, as shown in Figure 5, when the relative displacement between the left and right wheels is relatively small, such as when turning on a flat road, the rigidity of the stabilizer link 20 on the inside in the turning direction, which receives a load in the extension direction (when turning in Figure 5), is ensured, thereby improving handling stability.

[0018] The stabilizer link 20 on the outer side in the turning direction is restricted from contracting by the inner wall 27, so the rigidity of the stabilizer device 10 is not reduced. When the relative displacement between the left and right wheels is relatively large, such as when the vehicle is traveling on a rough road, the increase in the rigidity of the stabilizer device 10 that accompanies the increase in the relative displacement between the left and right wheels is suppressed (shown by A for rough road traveling in FIG. 5 ), and the relative displacement between the left and right wheels, particularly downward movement of the wheels, is permitted, thereby improving the road-holding performance of the wheels when traveling on a rough road. Note that, as a comparative example, if the stabilizer link 20 does not have the spring 24 and the joints 25 and 26 are simply connected by a rod, the stabilizer link 20 does not expand or contract. Therefore, even when the relative displacement between the left and right wheels is relatively large, such as when the vehicle is traveling on a rough road, the torsional rigidity of the stabilizer arm 11 increases uniformly as the relative displacement between the left and right wheels increases, and the rigidity of the entire stabilizer device 10 also increases (shown by B in FIG. 5 ). Therefore, in the comparative example, the increase in the relative displacement between the left and right wheels is suppressed when the vehicle is traveling on a rough road, whereas in this embodiment, the increase in the rigidity of the stabilizer device 10 is suppressed as described above, and the wheels are more likely to move downward.

[0019] As described above, in the stabilizer device 10 of this embodiment, the stabilizer links 20 provided at both ends of the stabilizer arm 11 have pistons 22 that are movable within the cylinders 21 and are extendable within a predetermined range. The pistons 22 are urged by the springs 24 in the direction of contracting the stabilizer link 20, and even if the stabilizer link 20 receives a force in the direction of extension, the stabilizer link 20 remains contracted as long as the force is equal to or less than the urging force of the springs 24. When the stabilizer link 20 receives a force in the direction of extension that exceeds the urging force of the springs 24, the stabilizer link 20 extends.

[0020] As described above, the stabilizer link 20 has a nonlinear characteristic, and its extension amount does not just change in response to the load it receives, i.e., in response to changes in the relative displacement between the left and right axles, but rather changes dramatically, thereby significantly changing the rigidity of the stabilizer device 10. For example, when the difference in displacement between the left and right wheels (tires) is small and the expansion / contraction load acting on the stabilizer link 20 is below a predetermined amount, the rigidity of the stabilizer device 10 can be increased to suppress roll and improve handling stability. When the difference in displacement between the left and right wheels is large and the expansion / contraction load acting on the stabilizer link 20 is above a predetermined amount, the rigidity of the stabilizer device 10 is weakened. In particular, by allowing the stabilizer link 20 to extend in the extension direction, the rigidity of the stabilizer device 10 can be weakened, allowing greater relative displacement between the left and right wheels, making it easier for the wheels to move downward during rebound, thereby improving wheel ground contact. In this way, the stabilizer device 10 having the stabilizer link 20 with a simple structure can achieve both improved handling stability and improved drivability on rough roads.

[0021] FIG. 6 is a vertical cross-sectional view showing the structure of a stabilizer link 30 according to the second embodiment. As shown in Figure 6, the stabilizer link 30 of the second embodiment has a cylindrical cylinder 31, a rod 23 having a joint 25 at one end and a piston 22 (first piston) at the other end, and a rod 33 having a joint 26 at one end and a piston 32 (second piston) at the other end.

[0022] The two rods 23, 33 are arranged on the same straight line as the axis of the cylinder 31, and the two pistons 22, 32 are arranged facing each other within the cylinder 31 and slidable in the axial direction within the cylinder 31. A biasing means 35, such as rubber, is provided between the piston 32 and an inner wall 34 at one axial end of the cylinder 31. The biasing means 35 biases the piston 32 toward the other piston 22. A biasing means 35 is also provided between the other piston 22 and an inner wall 36 at the other end of the cylinder 31. Note that the biasing means 35 may be a magnet instead of rubber, which biases the pistons 32, 22 in directions that bring them closer to each other, or both rubber and a magnet may be used.

[0023] In the second embodiment, the two pistons 22, 32 are pressed by the biasing means 35 in a state where the stabilizer link 30 is not subjected to a load in the extension / contraction direction. When a load equal to or less than the biasing force of the biasing means 35 is applied in the direction in which the stabilizer link 30 extends, the stabilizer link 30 does not extend, and when a load exceeding the biasing force of the biasing means 35 is applied in the direction in which the stabilizer link 30 extends, the stabilizer link 30 extends.

[0024] Therefore, similar to the stabilizer device 10 using the stabilizer link 20 of the first embodiment, when the relative displacement between the left and right wheels is relatively small, such as when turning on a flat road, the stabilizer device 10 using the stabilizer link 30 of the second embodiment suppresses the extension of the stabilizer link 30 on the inside of the turning direction, which receives a load in the extension direction, and the rigidity of the stabilizer device 10 increases as the relative displacement increases, thereby improving handling stability.

[0025] In the stabilizer link 30 on the outer side in the turning direction, the two pistons 22, 32 come into contact with each other to restrict further contraction, so that the rigidity of the stabilizer device 10 is not reduced. When the relative displacement between the left and right wheels is relatively large, such as when driving on rough roads, the stabilizer link 30 is extended to reduce the rigidity of the stabilizer device 10, as in the stabilizer device 10 using the stabilizer link 20 of the first embodiment, and the relative displacement between the left and right wheels is allowed to move, making it easier for the wheels to move downward during rebound, thereby improving the wheel's ground contact.

[0026] FIG. 7 is a vertical cross-sectional view showing the structure of a stabilizer link 40 according to the third embodiment. The stabilizer link 20 of the first embodiment and the stabilizer link 30 of the second embodiment are configured to urge the stabilizer links 20, 30 in a contracting direction by a spring 24 or a biasing means 35, but as shown in Figure 7, the stabilizer link 40 of the third embodiment is urged by a spring 24 in an extending direction.

[0027] When no load is applied to the stabilizer link 40, the biasing force of the spring 24 causes the piston 22 to contact the inner wall 28 of the cylinder 21 on the joint 25 side. If the displacement at this time is taken as 0, when the load in the direction compressing the stabilizer link 40 is equal to or less than the biasing force of the spring 24, the piston 22 moves very little and the stabilizer link 40 hardly compresses. When the load in the direction compressing the stabilizer link 40 exceeds the biasing force of the spring 24, the stabilizer link 40 compresses in accordance with the increase in load.

[0028] In the stabilizer device 1 using the stabilizer link 40 of the third embodiment, when the relative displacement between the left and right wheels is relatively small, such as when turning on a flat road, the contraction of the stabilizer link 40 on the outer side in the turning direction, which receives a load in the contracting direction, is restricted. This ensures the rigidity of the stabilizer device 1, and improves the handling stability. The stabilizer link 40 on the inner side in the turning direction is restricted in extension by the piston 22 abutting against the inner wall 28, so the rigidity of the stabilizer device 10 is not reduced.

[0029] When the relative displacement between the left and right wheels is relatively large, such as when driving on rough roads, the stabilizer link 40 expands and contracts, reducing the rigidity of the stabilizer device 1 and allowing the relative displacement between the left and right wheels to move, thereby improving the wheel's ability to grip the ground. The stabilizer device 10 of the above embodiment restricts the expansion and contraction of the stabilizer links 20, 30, 40 when an expansion and contraction load of a predetermined amount or less is applied, thereby suppressing twisting of the stabilizer arm 11 when the relative displacement between the left and right axles is relatively small, thereby increasing the rigidity of the stabilizer device 10 and improving handling stability.

[0030] In addition, by allowing the stabilizer links 20, 30, 40 to expand and contract in a direction that reduces the rigidity of the stabilizer device 10 when an expansion and contraction load exceeding a predetermined amount is applied, twisting of the stabilizer arm 11 is allowed when the relative displacement between the left and right axles is relatively large, such as when driving on rough roads, thereby improving the wheel's ground contact and traveling performance. In this way, in the vehicle stabilizer device 10, the springs 24 and biasing means 35 of the stabilizer links 20, 30, 40 are installed with a preload, and the stabilizer links 20, 30, 40 have nonlinear characteristics, thereby making it possible to achieve both improved vehicle handling stability and improved vehicle performance on rough roads.

[0031] In addition, the stabilizer links 20, 30, 40 are equipped with cylinders 21, 31 and pistons 22, 32 arranged slidably within the cylinders 21, 31, and by using a biasing means such as a spring, rubber, or magnet to bias the pistons 22, 32, the rigidity of the stabilizer device 10 can be changed with a simple structure, and the contradictory functions of ensuring steering stability by ensuring rigidity during cornering and improving wheel ground contact by weakening rigidity when driving on rough roads can be achieved simultaneously with a simple structure.

[0032] The present invention is not limited to the above-described embodiments. For example, in the above embodiment, the present invention is applied to a stabilizer device used in a double wishbone suspension system, but the present invention may also be applied to stabilizer devices used in other types of suspension systems. The present invention is also applicable to both front and rear wheel suspension devices of a vehicle.

[0033] The present invention can be widely applied to stabilizer devices that include stabilizer arms that connect support portions of left and right axles, with stabilizer links attached to both ends of the stabilizer arms. [Explanation of symbols]

[0034] 7 Knuckle (support part) 10. Stabilizer device 11 Stabilizer arm 20, 30, 40 stabilizer link 21, 31 cylinders 22 Piston (1st piston) 24 Spring (biasing means) 35 Actuation means 32 Piston (2nd piston)

Claims

1. a stabilizer arm that connects support parts that support the left and right axles of the vehicle and suppresses the difference in displacement between the left and right axles by torsional rigidity; a stabilizer link interposed between each end of the stabilizer arm and the support portion, the stabilizer link is extendable and includes a biasing means for biasing the stabilizer link in an extending or contracting direction, a preload is applied to the biasing means so that the stabilizer link expands or contracts in a direction that reduces the rigidity of the stabilizer device when a load exceeding a predetermined amount acts on the stabilizer link in an expanding or contracting direction, and the stabilizer link has non-linear characteristics; A stabilizer device characterized by:

2. The stabilizer link includes a cylindrical cylinder and a piston slidably disposed within the cylinder, and extends and contracts due to the sliding of the cylinder and the piston. The biasing means is a spring that is disposed in the cylinder and biases the piston in a direction that compresses the stabilizer link.

2. The stabilizer device according to claim 1, wherein:

3. The stabilizer link includes a cylindrical cylinder and a piston slidably disposed within the cylinder, and extends and contracts due to the sliding of the cylinder and the piston. The biasing means is a spring that is disposed in the cylinder and biases the piston in a direction that extends the stabilizer link.

2. The stabilizer device according to claim 1, wherein:

4. The stabilizer link has a cylindrical cylinder, and a first piston and a second piston each slidably disposed in the cylinder in the axial direction, and the stabilizer link expands and contracts due to relative movement between the first piston and the second piston, The biasing means is a rubber member that is disposed inside the cylinder and that restricts the expansion and contraction of the stabilizer arm when an expansion and contraction load equal to or less than the predetermined amount is applied.

2. The stabilizer device according to claim 1, wherein:

5. The stabilizer link has a cylindrical cylinder, and a first piston and a second piston respectively slidably disposed within the cylinder, and the stabilizer link expands and contracts due to relative movement between the first piston and the second piston, The biasing means is a magnet that is disposed in the cylinder and is installed so as to attract the first piston and the second piston.

2. The stabilizer device according to claim 1, wherein:

Images