Vehicle door support device

Abstract

The axial load of the active support member and the axial load of the passive support member are equalized. [Solution] The door support device 5 comprises an active first support member 6A and a passive second support member 6B. The first coil spring 23A of the first support member 6A and the second coil spring 23B of the second support member 6B are configured such that the spring load difference ΔP(θCL) at the fully closed position θCL is smaller than the spring load difference ΔP(θOP) at the fully open position θOP, and the second spring load P2(θOP) at the fully open position θOP is larger than the first spring load P1(θOP).

Description

Technical Field

[0001] The present invention relates to a vehicle door support device.

Background Art

[0002] Patent Document 1 discloses a vehicle door support device that supports a door with respect to a vehicle body. The door support device includes an active support member attached to one side in the width direction and a passive support member attached to the other side in the width direction. Each support member includes a fixed housing, a movable housing, a coil spring that advances the movable housing from the fixed housing, a spindle attached to the fixed housing, and a spindle nut attached to the movable housing.

[0003] The active support member includes a motor that rotationally drives the spindle, and the movable housing actively moves forward and backward with respect to the fixed housing. The passive support member does not include a motor, and the movable housing moves forward and backward passively with respect to the fixed housing. The passive support member includes a brake that imparts rotational resistance to the spindle instead of a motor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] If there is a difference between the axial load of the active support member and the axial load of the passive support member, a load may act on the door due to this axial load difference, which may affect the stable operation of the door. In the above door support device, there is room for improvement in equalizing the axial load of the active support member and the axial load of the passive support member.

[0006] The present invention aims to equalize the axial load of an active support member and the axial load of a passive support member. [Means for solving the problem]

[0007] One embodiment of the present invention comprises a first support member and a second support member for supporting a door with respect to a vehicle body, the first support member and the second support member each comprising: a cylindrical fixed housing having a first end connected to one of the vehicle body and the door and a second end opposite to the first end; a cylindrical movable housing having a third end connected to the other of the vehicle body and the door, housed in the fixed housing from the second end on the opposite side of the third end and movable in the axial direction relative to the fixed housing; a spindle rotatably supported within the fixed housing; a spindle nut screwed onto the spindle and connected to the movable housing; and a coil spring biasing the movable housing toward the direction toward the direction toward the fixed housing, wherein the first support member is an active support member equipped with a motor for driving the spindle of the first support member, and the second support member The present invention provides a vehicle door support device in which the material is a passive support member that moves in accordance with the operation of the door, the coil spring of the first support member is defined as the first coil spring, the component of the first axial load acting from the first coil spring to the first support member is defined as the first spring load, the coil spring of the second support member is defined as the second coil spring, the component of the second axial load acting from the second coil spring to the second support member is defined as the second spring load, and the difference between the first spring load and the second spring load at the same door position is defined as the spring load difference, wherein the first coil spring and the second coil spring are configured such that the spring load difference when the door is in the fully closed position is smaller than the spring load difference when the door is in the fully open position, and the second spring load is larger than the first spring load when the door is in the fully open position.

[0008] In the above configuration, the motor is stopped when the door is held in the fully closed position. The first axial load of the first support device (active support device) is equivalent to the first spring load, and the second axial load of the second support device (passive support device) is equivalent to the second spring load. When the door is in the fully closed position, the difference in spring loads is relatively small. Therefore, when the door is held in the fully closed position, the difference between the first and second axial loads becomes small, and the load acting on the door due to the difference in axial loads is reduced. Furthermore, for most of the practical use of the vehicle and the door support device, the door is held in the fully closed position. Therefore, achieving equalization of axial loads in the fully closed position is particularly beneficial.

[0009] During the automatic opening operation using the motor, the operating force is generated as a positive component of the first axis load, based on the motor's driving force. The second axis load does not include the operating force. When the door is in the fully open position, the second spring load becomes larger than the first spring load, and the spring load difference becomes relatively large. This spring load difference cancels out the operating force added to the first axis load. Therefore, during the automatic opening operation, the second axis load can be brought closer to the first axis load.

[0010] During the motor-driven automatic closing operation, the operating force is included as a negative component in the first shaft load. The second shaft load does not include the operating force. The difference in spring load at the fully closed position is smaller than the difference in spring load at the fully open position. Therefore, during the automatic closing operation, especially towards the end, the first shaft load can be brought closer to the second shaft load. [Effects of the Invention]

[0011] According to the present invention, the axial load of the active support member and the axial load of the passive support member can be equalized. [Brief explanation of the drawing]

[0012] [Figure 1] A rearward perspective view of a vehicle equipped with a vehicle door support device according to an embodiment. [Figure 2] Schematic diagram of the door support device shown in Figure 1. [Figure 3] Cross-sectional view of the first support member in Figure 1. [Figure 4] Cross-sectional view of the second support member in Figure 1. [Figure 5] A graph showing the axial load on the door position during automatic opening operation. [Figure 6] A graph showing the axial load on the door position during automatic closing operation. [Figure 7] A graph showing the axial load on the door position during manual opening operation. [Figure 8] A graph showing the axial load on the door position during manual closing operation. [Modes for carrying out the invention]

[0013] Embodiments will be described below with reference to the drawings. Note that identical or corresponding elements are denoted by the same reference numerals, and redundant detailed descriptions are omitted.

[0014] Referring to Figure 1, the door support device 5 according to this embodiment is applied to a vehicle 1 and supports the door 3 relative to the vehicle body 2. The door 3 is supported by the door support device 5 so as to be displaceable relative to the vehicle body 2 between a fully closed position in which the opening 2a of the vehicle body 2 is completely closed and a fully open position in which the opening 2a is fully open.

[0015] The operation of door 3 includes automatic operation (see Figures 5 and 6) caused by the driving force of the motor 31 of the door support device 5 (see Figure 2), and manual operation (see Figures 7 and 8) caused by external forces other than the driving force of the motor 31 (typically, the operating force of the user of vehicle 1). The operation of door 3 includes an opening operation (see Figures 5 and 7) in which the door position θ changes toward the fully open position θOP, and a closing operation (see Figures 6 and 8) in which the door position θ changes toward the fully closed position θCL.

[0016] Door 3 is provided with a latch mechanism 4 that detachably holds the striker 2b of the vehicle body 2. The striker 2b is located on the periphery of the opening 2a. When door 3 reaches the fully closed position through the closing operation, the fully closed state is maintained by the action of the latch mechanism 4.

[0017] As an example, the opening 2a is provided at the rear of the vehicle body 2 and opens the passenger compartment or the cargo compartment to the rear. The door 3 is a back door that closes the opening 2a in an openable manner. The back door is also referred to as a rear gate. The back door or rear gate is pivotally attached to the vehicle body 2 by a hinge connection, and its rotation axis extends in the vehicle width direction at the upper edge of the opening 2a. The striker 2b is provided at the lower edge of the opening 2a. The door position θ is quantitatively represented as an angle (deg) around the rotation axis.

[0018] The door support device 5 includes a pair of support members 6 that support the door 3 with respect to the vehicle body 2. One end of the support member 6 is pivotally connected to the vehicle body 2, and the other end of the support member 6 is pivotally connected to the door 3. The support member 6 is configured as an extendable and retractable rod body. In the opening operation, the support member 6 extends. In the closing operation, the support member 6 contracts.

[0019] The pair of support members 6 are arranged apart from each other in the vehicle width direction. In the illustrated example, the first support member 6A is arranged on the right side and the second support member 6B is arranged on the left side, but this arrangement may be reversed left and right.

[0020] The first support member 6A is a so-called active support member and incorporates a motor 31 (see FIG. 2). The second support member 6B is a so-called passive support member that follows the movement of the door 3 and does not include a motor.

[0021] Referring to FIGS. 2 to 4, the first support member 6A and the second support member 6B each include a fixed housing 10, a movable housing 15, a spindle 21, a spindle nut 22, a coil spring 23, and a brake 24. These members are coaxially arranged on the central axis C6 of the support member 6.

[0022] In the following explanation, when referring to elements of the first support member 6A that are common to both the first support member 6A and the second support member 6B, the ordinal number "1st" may be added to the name of the element and the subscript "A" may be added to the symbol of the element. Similarly, the ordinal number "2nd" and subscript "B" may be used for the second support member 6B. When the first support member 6A and the second support member 6B are not distinguished, the ordinal number and subscript may be omitted without further explanation.

[0023] In the following description, with respect to the axial direction of the support member 6, the side approaching the connection partner of the fixed housing 10 is referred to as the "base end side," and the side moving away from the connection partner of the fixed housing 10 is referred to as the "end end side." In this embodiment, the fixed housing 10 is connected to the vehicle body 2, and the movable housing 15 is connected to the door 3, with the vehicle body side being the base end side. However, the fixed housing 10 may be connected to the door 3 and the movable housing 15 may be connected to the vehicle body 2, in which case the door side is the base end side.

[0024] The fixed housing 10 and the movable housing 15 are cylindrical. The fixed housing 10 has a first end 10a connected to the vehicle body 2 and a second end 10b opposite to the first end 10a. The movable housing 15 has a third end 15a connected to the door 3. The movable housing 15 is housed in the fixed housing 10 from the second end 10b on the side opposite to the third end 15a and is movable axially relative to the fixed housing 10.

[0025] The spindle 21 is housed within the fixed housing 10 and is rotatably supported relative to the fixed housing 10 around a central axis C6. The spindle nut 22 is screwed onto the spindle 21. The spindle nut 22 is connected to the end of the movable housing 15 via a push rod 16. The spindle nut 22 is supported by a guide 11 fixed to the fixed housing 10 in a manner that allows for axial displacement but prevents rotation.

[0026] The coil spring 23 biases the movable housing 15 in a direction that moves it out of the fixed housing 10. The brake 24 mechanically applies rotational resistance to the spindle 21 as the movable housing 15 moves relative to the fixed housing 10.

[0027] The fixed housing 10 has a partition portion 12 inside its base end, and a cylindrical housing portion 13 is formed on the base end side (lower side of the paper in Figure 2) relative to the partition portion 12. The brake 24 is housed in the housing portion 13 and is adjacent to the partition portion 12. One end of the spindle 21 passes through the partition portion 12 and enters the housing portion 13. The brake 24 is attached to the outer circumference of one end of the spindle 21.

[0028] The first support member 6A includes a motor 31 that generates a driving force to drive the first spindle 21A, and a gear mechanism 32 that transmits the rotation of the motor 31 to the first spindle 21A. The motor 31, the gear mechanism 32, and the first brake 24A are housed in the first housing 13A in this order from the base end in the axial direction. One end of the first spindle 21A is connected to the gear mechanism 32, and via the gear mechanism 32, it is connected to the motor 31.

[0029] The second support member 6B does not include a motor or gear mechanism. Instead, the second support member 6B may include a spacer 36. The spacer 36 may be housed in the second housing 13B and positioned on the base end side of the second brake 24B.

[0030] The coil spring 23 is housed inside the fixed housing 10 and the movable housing 15 in a compressed state from its natural length. The base end of the coil spring 23 is supported by the fixed housing 10 at a position adjacent to the end end (upper side of the paper in Figure 2) relative to the partition 12. The end end of the coil spring 23 is supported by the end end of the movable housing 15. When the door 3 is operated, the amount the movable housing 15 extends relative to the fixed housing 10 changes, the spring length changes, and the spring force exerted by the coil spring 23 changes. In the fully closed state, the spring length is minimized and the spring force is maximized, and in the fully open state, the spring length is maximized and the spring force is minimized.

[0031] Depending on the displacement of the door 3, the overall length of the support member 6 (the axial distance from the connection point with the vehicle body 2 to the connection point with the door 3) and the orientation of the support member 6 relative to the vehicle body 2 change. At any door position (i.e., normally), the first support member 6A and the second support member 6B are parallel and have the same overall length. At any door position, the distance from the connection point with the door 3 to the position supporting the end of the coil spring 23 is the same for both the first support member 6A and the second support member 6B.

[0032] On the other hand, due to the presence or absence of the motor 31, the first housing section 13A is longer than the second housing section 13B, and the first partition section 12A is located on the end side relative to the second partition section 12B. Consequently, at any door position, the distance from the connection point with the vehicle body 2 to the position supporting the base end of the coil spring 23 is longer for the first support member 6A than for the second support member 6B.

[0033] Therefore, at any door position, the first spring length L1(θ) of the first coil spring 23A is shorter than the second spring length L2(θ) of the second coil spring 23B. The difference between the first spring length L1(θ) and the second spring length L2(θ) can be adjusted by adjusting the axial length of the spacer 36, thereby adjusting the position of the second partition 12B.

[0034] In the manual opening operation, both the first support member 6A and the second support member 6B move in accordance with the displacement of the door 3. The movable housing 15 is pulled out from the fixed housing 10, and the push rod 16 moves toward the end along the guide 11 together with the spindle nut 22. The translation of the spindle nut 22 is converted into the rotation of the spindle 21, causing the spindle 21 to rotate in the opening direction.

[0035] In the manual closing operation, both the first support member 6A and the second support member 6B move in accordance with the displacement of the door 3. The movable housing 15 is pushed into the fixed housing 10, and the push rod 16 moves toward the base end along the guide 11 together with the spindle nut 22. The translation of the spindle nut 22 is converted into the rotation of the spindle 21, causing the spindle 21 to rotate in the closing direction, opposite to the opening direction.

[0036] Regarding the automatic opening operation, in the active first support member 6A, the motor 31 rotates in the opening direction. The driving force of the motor 31 is transmitted to the first spindle 21A via the gear mechanism 32, and the first spindle 21A is rotated in the opening direction. The rotation of the first spindle 21A is converted into translation of the first spindle nut 22A, and the first spindle nut 22A moves toward the end along the first guide 11A. As a result, the first movable housing 15A is pushed out from the first fixed housing 10A, and the door position changes toward the fully open position.

[0037] The passive second support member 6B moves in accordance with the displacement of the door 3. The second movable housing 15B is pulled out from the second fixed housing 10B, and the second spindle nut 22B moves toward the end along the second guide 11B. As a result, the amount of extension of the second movable housing 15B follows the amount of extension of the first movable housing 15A, and at any door position, the first support member 6A and the second support member 6B become parallel and of equal length. The translation of the second spindle nut 22B is converted into the rotation of the second spindle 21B, causing the second spindle 21B to rotate in the opening direction.

[0038] Regarding the automatic closing operation, in the active first support member 6A, the motor 31 rotates in the closing direction. The driving force of the motor 31 is transmitted to the first spindle 21A via the gear mechanism 32, and the first spindle 21A is rotated in the closing direction. The rotation of the first spindle 21A is converted into translation of the first spindle nut 22A, and the first spindle nut 22A moves toward the base end along the first guide 11A. As a result, the first movable housing 15A is pulled into the first fixed housing 10A, and the door position changes toward the fully closed position.

[0039] The passive second support member 6B is driven by the displacement of the door 3. The second movable housing 15B is pushed into the second fixed housing 10B, and the second spindle nut 22B moves toward the base end along the second guide 11B. The translation of the second spindle nut 22B is converted into the rotation of the second spindle 21B, causing the second spindle 21B to rotate in the closing direction.

[0040] In this embodiment, the brake 24 applies rotational resistance to the spindle 21 in any of the four operations described above, using either the first support member 6A or the second support member 6B.

[0041] Referring to Figures 3 and 4, in this embodiment, the brake 24 comprises a rotating member 24a that rotates integrally with the spindle 21 relative to the fixed housing 10, and a sliding contact member 24b that is fixed to the fixed housing 10 and slidably contacts the outer circumferential surface of the rotating member 24a. The brake 24 further comprises a brake case 24c that houses the rotating member 24a and the sliding contact member 24b and is attached to the fixed housing 10.

[0042] The spindle 21 has a flat connecting end 21a at one end, and the connecting end 21a is inserted into a non-circular through hole 24d that penetrates the rotating member 24a. As a result, the rotating member 24a is fitted to the spindle 21 in the rotational direction and rotates integrally with the spindle 21. The first connecting end 21Aa of the first spindle 21A is connected to the gear mechanism 32 (see Figure 3).

[0043] The outer circumferential surface of the rotating member 24a is cylindrical. The sliding contact member 24b is, for example, a coil spring, and is positioned to surround the outer circumference of the rotating member 24a, elastically tightening against the outer circumferential surface of the rotating member 24a. Both ends of the coil spring acting as the sliding contact member 24b are supported by the brake case 24c. When the spindle 21 rotates, the rotating member 24a slides against the sliding contact member 24b. The friction between the rotating member 24a and the sliding contact member 24b is applied to the spindle 21 as rotational resistance.

[0044] Returning to Figure 2, we will now explain the axial load generated on the support member 6 during the practical use of the door support device 5. The tensile component is considered positive, and the compressive component is considered negative.

[0045] The first axial load σ1 of the first support member 6A mainly consists of a first spring load P1(θ) based on the spring force exerted by the first coil spring 23A and a first braking force τ1 based on the rotational resistance generated by the first brake 24A. The first axial load σ1 may further include an operating force FM(θ) based on the thrust generated in the spindle nut 22 or push rod 16 by the driving force of the motor 31.

[0046] The second axial load σ2 of the second support member 6B mainly consists of a second spring load P2(θ) based on the spring force exerted by the second coil spring 23B and a second braking force τ2 based on the rotational resistance generated by the second brake 24B.

[0047] The first spring load P1(θ) is generated both while the door 3 is operating and while it is stopped. The first spring load P1(θ) changes depending on the door position θ. At any door position θ, the spring force acts in the direction that advances the first movable housing 15A, that is, in the tensile direction of the first support member 6A. Therefore, at any door position θ, the first spring load P1(θ) is the positive component of the first axial load σ1, regardless of whether it is in opening, closing, or stopped operation. The relationship between the second spring load P2(θ) and the second axial load σ2 is similar.

[0048] The first braking force τ1 occurs during the operation of door 3, but not when door 3 is stopped. The first braking force τ1 is a negative component of the first axle load σ1 during the opening operation, while it is a positive component of the first axle load σ1 during the closing operation. The relationship between the second braking force τ2 and the second axle load σ2 is similar.

[0049] The operating force FM(θ) is included only in the first axis load σ1 during automatic operation. The operating force FM(θ) is not included in the second axis load σ2 even during automatic operation, and does not occur during manual operation or when the door 3 is stopped. The operating force FM(θ) has a component in the opposite direction to the braking force. During automatic opening operation, the operating force FM(θ) is a positive component of the first axis load σ1, while during automatic closing operation, it is a negative component of the first axis load σ1. The operating force FM(θ) changes according to the direction of operation of the door 3 and also according to the door position θ.

[0050] If there is a difference between the first axial load σ1 and the second axial load σ2 (hereinafter referred to as the axial load difference), a load acts on the door 3, and this load attempts to deform the door 3. If the rigidity of the door 3 is sufficiently high, the deformation of the door 3 will be prevented against the load. However, in recent years, doors 3 have been getting larger, and the use of resin in the components of the door 3 has been increasing. In light of this recent trend, the effect of the axial load difference on the deformation of the door 3 may become larger. If deformation occurs in the door 3, it may affect the operation of the door 3, for example, by causing the latch mechanism 4 to shift position relative to the striker 2b.

[0051] Therefore, the door support device 5 according to this embodiment is configured as follows in order to equalize the first axial load σ1 and the second axial load σ2.

[0052] In the following explanation, the difference between the first spring load P1(θ) and the second spring load P2(θ) at the same door position θ will be referred to as the "spring load difference ΔP(θ)". Note that the coil spring 23 is made of metal, and its elastic modulus changes with temperature. Unless otherwise specified, the spring load and related physical quantities (e.g., spring constant) will be described assuming the same predetermined temperature environment (e.g., 20°C).

[0053] In this embodiment, the spring load difference ΔP(θCL) in the fully closed state is smaller than the spring load difference ΔP(θOP) in the fully open state. For example, the first coil spring 23A and the second coil spring 23B are configured such that the spring load difference ΔP(θCL) in the fully closed state is zero. That is, the first coil spring 23A and the second coil spring 23B are configured such that the first spring load P1(θCL) and the second spring load P2(θCL) are equal in the fully closed state.

[0054] When door 3 is held in the fully closed position, the first axial load σ1 is equal to the first spring load P1(θCL), and the second axial load σ2 is equal to the second spring load P2(θCL). The difference in axial loads is small, for example, zero. Therefore, the load acting on door 3 due to the difference in axial loads can be reduced or eliminated. Even if the rigidity of door 3 is low, deformation of door 3 can be prevented or suppressed. During the practical use of vehicle 1, door 3 is held in the fully closed position for most of the time. Since the difference in axial loads can be reduced or eliminated for most of this time, it is very beneficial for the door support device 5.

[0055] Here, the amount of extension of the movable housing 15 from the fully closed state to the fully open state is the same for both the first support member 6A and the second support member 6B. Therefore, the amount of extension of the coil spring 23 (change in spring length) from the fully closed state to the fully open state is the same for both the first support member 6A and the second support member 6B.

[0056] On the other hand, the first spring constant of the first coil spring 23A is set higher than the second spring constant of the second coil spring 23B. The spring constant can be adjusted as appropriate by adjusting or selecting, for example, the spring pitch, the spring wire diameter, the spring outer diameter, the spring material, etc.

[0057] Because the extension is the same but the spring constants are different, the damping of the first spring load P1(θ) from the fully closed state to the fully open state is greater than the damping of the second spring load P2(θ). In the fully open state, the second spring load P2(θOP) is greater than the first spring load P1(θOP). Also, as described above, the spring load difference ΔP(θOP) in the fully open state is greater than the spring load difference ΔP(CL) in the fully closed state.

[0058] Furthermore, the amount of contraction from the natural length in the fully closed state is smaller for the first coil spring 23A than for the second coil spring 23B. This makes it possible to make the spring force in the fully closed state the same while using different spring constants. Since both the amount of contraction from the natural length and the spring length after contraction are shorter for the first coil spring 23A, the natural length of the first coil spring 23A is also shorter.

[0059] Furthermore, the first brake 24A and the second brake 24B are configured such that the first braking force τ1 is greater than the second braking force τ2. The braking force can be adjusted as appropriate, for example, by changing the number of turns or wire diameter of the coil spring as the sliding contact member 24b. As an example of using this adjustment method, the number of turns in the first brake 24A is greater than the number of turns in the second brake 24B.

[0060] Figures 5 to 8 show the first axle load σ1 and the second axle load σ2 with respect to the door position θ during automatic opening, automatic closing, manual opening, and manual closing operations, respectively. It is assumed that the vehicle 1 is in contact with the horizontal ground. Figures 5 and 7 show the door position θ changing from left to right over time during the opening operation. Figures 6 and 8 show the door position θ changing from right to left over time during the closing operation. The solid line represents the first axle load σ1, and the dashed line represents the second axle load σ2. There is variation in the rotational resistance of the brake 24. The thick line shows the axle load when the rotational resistance is the median or average value, and the thin line shows the axle load when the rotational resistance is the maximum or minimum value within the variation range.

[0061] Referring to Figures 5 and 7, in the passive second support member 6B, the second axial load σ2 is substantially the same in both the automatic opening operation and the manual opening operation. As the door position θ approaches the fully open position θOP, the second axial load σ2 decreases smoothly downwards to the right due to the decrease in the second spring load P2(θ).

[0062] Referring to Figure 7, in the manual opening operation, in the active first support member 6A, as with the second support member 6B, the first axial load σ1 gradually decreases due to the decrease in the first spring load P1(θ) as the door position θ approaches the fully open position θOP. Since the first spring constant is larger than the second spring constant, the degree of decrease in the first axial load σ1 is greater than that of the second axial load σ2, and the spring load difference ΔP(θ) gradually increases. Since the first braking force τ1 is larger than the second braking force τ2, and both the first and second braking forces τ1 and τ2 have negative components, the first axial load σ1 remains lower than the second axial load σ2.

[0063] Referring to Figure 5, in the active first support member 6A during the automatic release operation, the actuation force FM(θ) is added to the first axial load σ1 as a positive component. As can be seen by referring to Figure 5 in conjunction with Figure 7, the actuation force FM(θ) changes along a downward-convex curve, and this trend of the actuation force FM(θ) is reflected in the trend of the first axial load σ1.

[0064] Here, the door position exactly halfway between the fully closed position θCL and the fully open position θOP is defined as the "intermediate position θm". As can be seen from the trend of the first axis load σ1, the operating force FM(θ) is high at the start of the auto-opening operation and decreases sharply in the initial stages of the auto-opening operation. The operating force FM(θ) changes from decreasing to increasing around the intermediate position θm. In the latter stages of the auto-opening operation, the operating force FM(θ) gradually increases until the door position θ reaches the fully open position θOP.

[0065] The positive component of the operating force FM(θ) cancels out the difference between the negative components of the first braking force τ1 and the second braking force τ2. Conversely, because the first braking force τ1 is set to be larger than the second braking force τ2, the operating force FM(θ) input during the automatic release operation is canceled out by the relatively large first braking force τ1.

[0066] Furthermore, the gradual increase in the operating force FM(θ) during the latter stages of the automatic release operation cancels out the gradual increase in the spring load difference ΔP(θ). Conversely, the spring load difference ΔP(θOP) in the fully open state is made larger than the spring load difference ΔP(θCL) in the fully closed state, and the second spring load P2(θOP) in the fully open state is made larger than the first spring load P1(θOP). As a result, the gradual increase in the operating force FM(θ) during the automatic release operation is canceled out by the gradual increase in the spring load difference ΔP(θ) and the relatively small first spring load P1(θOP).

[0067] In this way, during the automatic release operation, the first axial load σ1 is brought close to the second axial load σ2. In particular, the first axial load σ1 temporarily becomes equal to the second axial load σ2 at the first position θ1 in the initial rapid decrease section. The first axial load σ1 becomes equal to the second axial load σ2 again at the second position θ2 in the later gradual increase section. The first position θ1 is closer to the fully closed position θCL than the intermediate position θm, and the second position θ2 is closer to the fully open position θOP than the intermediate position θm. The axial load difference is kept small throughout the entire automatic release operation from the fully closed position θCL to the fully open position θOP.

[0068] Referring to Figures 6 and 8, in the passive second support member 6B, the second axial load σ2 is substantially the same in both the automatic closing operation and the manual closing operation. As the door position θ approaches the fully closed position θCL, the second axial load σ2 increases smoothly to the left due to the increase in the second spring load P2(θ).

[0069] Referring to Figure 8, in manual closing operation, in the active first support member 6A, as with the second support member 6B, the first axial load σ1 gradually increases due to the increase in the first spring load P1(θ) as the door position θ approaches the fully closed position θCL. Since the first spring constant is larger than the second spring constant, the degree of increase in the first axial load σ1 is greater than that of the second axial load σ2, and the spring load difference ΔP(θ) gradually decreases. Since the first braking force τ1 is larger than the second braking force τ2, and both the first and second braking forces τ1 and τ2 have positive components, the first axial load σ1 remains higher than the second axial load σ2.

[0070] Referring to Figure 6, in the active first support member 6A during the automatic closing operation, the actuation force FM(θ) is added to the first axial load σ1 as a negative component. As can be seen by referring to Figure 6 in conjunction with Figure 8, the absolute value of the actuation force FM(θ) changes along an upwardly convex curve. This trend of the actuation force FM(θ) acts as a negative component and is reflected in the trend of the first axial load σ1.

[0071] As can be seen from the inversion of the trend of the first axis load σ1, the absolute value of the operating force FM(θ) is high at the start of the automatic closing operation and gradually increases in the first half of the automatic opening operation. The absolute value of the operating force FM(θ) changes from increasing to decreasing around the intermediate position θm. In the final stage of the automatic closing operation, the absolute value of the operating force FM(θ) decreases sharply until the door position θ reaches the fully open position θOP. This trend of the absolute value is reflected in the trend of the first axis load σ1, in the form of an inversion of increase and decrease. The first axis load σ1 decreases gradually from a lower value than the second axis load σ2 and increases sharply towards the end.

[0072] The negative component of the operating force FM(θ) cancels out the difference between the positive components of the first braking force τ1 and the second braking force τ2. Conversely, because the first braking force τ1 is set to be larger than the second braking force τ2, the negative effect of the operating force FM(θ) in the automatic closing operation is canceled out by the relatively large first braking force τ1.

[0073] If the first braking force τ1 and the second braking force τ2 are equal, even if the first axle load σ1 increases sharply towards the end of the automatic closing operation, it may not be able to approach the second axle load σ2 sufficiently. In that case, deformation may occur in the door 3 due to the difference in axle load, which may interfere with the engagement between the latch mechanism 4 and the striker 2b. By setting the first braking force τ1 to be greater than the second braking force τ2, the first axle load σ1 can be brought closer to the second axle load σ2, especially towards the end of the automatic closing operation. Therefore, this contributes to the stable operation of the door 3.

[0074] As described above, according to this embodiment, the first coil spring 23A and the second coil spring 23B are configured such that the spring load difference ΔP(θCL) when the door position θ is in the fully closed position θCL is smaller than the spring load difference ΔP(θOP) when the door position θ is in the fully open position θOP. As a result, while the door position θ is held in the fully closed position θCL, i.e., for most of the time during which the vehicle 1 is in use, the axle load difference is relatively small, and the load acting on the door 3 due to the axle load difference can be reduced or eliminated.

[0075] In the above explanation, for the sake of ease of understanding, the spring load difference ΔP(θCL) in the fully closed state is given as an example of zero. This is merely one example. The spring load difference ΔP(θCL) in the fully closed state only needs to be set within a range that does not affect the deformation of door 3. For example, the value obtained by dividing the spring load difference ΔP(θCL) by the first spring load P1(θCL) or the second spring load P2(θCL) should be within the range of 10%, preferably 5%.

[0076] Furthermore, the first coil spring 23A and the second coil spring 23B are configured such that when the door position θ is in the fully open position θOP, the second spring load P2(θOP) is greater than the first spring load P1(θOP). As a result, during the automatic opening operation, the actuation force FM(θ), which is input as a positive component to the first shaft load σ1, is canceled out by the relatively larger second spring load P2(θOP). Therefore, during the automatic opening operation, the first shaft load σ1 and the second shaft load σ2 are equalized.

[0077] Furthermore, the first brake 24A and the second brake 24B are configured such that the first braking force τ1 is greater than the second braking force τ2.

[0078] As a result, during the automatic release operation, the operating force FM(θ), which is input as a positive component to the first shaft load σ1, is canceled out by the first braking force τ1, which is input as a negative component to the first shaft load σ1 and is relatively large. Combined with the fact that the second spring load P2(θOP) is relatively large in the fully open state, the first shaft load σ1 and the second shaft load σ2 are equalized during the automatic release operation.

[0079] Furthermore, during the automatic closing operation, the operating force FM(θ), which is input as a negative component to the first shaft load σ1, is offset by the relatively large first braking force τ1. Combined with the relatively small spring load difference ΔP(θCL) in the fully closed state, the first shaft load σ1 and the second shaft load σ2 are equalized during the automatic closing operation, especially towards the end of it.

[0080] Furthermore, in this embodiment, when the vehicle door support device consists of an active first support member 6A and a passive second support member 6B, both the first support member 6A and the second support member 6B are provided with brakes. Therefore, even if the unit becomes detached while compressed, either support member 6 can prevent rapid extension due to the action of the brakes. In this embodiment, the second brake force τ2 of the second support member 6B is set to be smaller than the first brake force τ1 of the first support member 6A, but by applying brakes to both, rapid extension can be effectively prevented.

[0081] The configuration of the embodiment described above is merely an example and can be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0082] 1 vehicle 2 car bodies 2a opening 2b Striker 3-door 4. Latch mechanism 5 Door support device 6. Support Member 6A First support member 6B Second support member 10 Fixed Housing 10a 1st end 10b 2nd end 10A First Fixed Housing 10B Second Fixed Housing 11 Guide 11A Guide 1 11B Guide 2 12 Partition section 12A First partition section 12B Second partition section 13. Detention Unit 13A First containment area 13B Second containment area 15. Movable Housing 15A First movable housing 15B Second movable housing 15a 3rd end 16 Pushrods 21 spindles 21a Connection end 21A First spindle 21Aa First connection end 21B Second spindle 22 Spindle nut 22A First spindle nut 22B Second spindle nut 23 Coil Springs 23A First coil spring 23B Second coil spring 24 Brake 24a Rotating member 24b Sliding contact member 24c brake case 24d through hole 24A First Brake 24Aa First rotating member 24B Second brake 31 Motor 32 Gear mechanism 36 Spacers C6 center axis FM(θ) Actuation force L1(θ) First spring length L2(θ) Second spring length P1(θ) First spring load P2(θ) Second spring load ΔP(θ) Spring load difference σ1 1st axis load σ2 2nd axis load θ Door position θCL Fully closed position θOP Fully open position θm intermediate position θ1 1st position θ2 2nd position τ1 First braking force τ2 Second braking force

Claims

1. The vehicle body is equipped with a first support member and a second support member that support the door, The first support member and the second support member are, A cylindrical fixed housing having a first end connected to one of the vehicle body and the door, and a second end on the opposite side of the first end, A cylindrical movable housing having a third end connected to the other of the vehicle body and the door, housed in the fixed housing from the second end on the opposite side of the third end, and movable in the axial direction relative to the fixed housing, A spindle rotatably supported within the aforementioned fixed housing, A spindle nut is screwed onto the spindle and connected to the movable housing, A coil spring biases the movable housing in a direction that extends it from the fixed housing, Equipped with, The first support member is an active support member equipped with a motor that drives the spindle of the first support member, and the second support member is a passive support member that moves in accordance with the operation of the door. When the coil spring of the first support member is defined as the first coil spring, the component of the first axial load acting from the first coil spring to the first support member is defined as the first spring load, the coil spring of the second support member is defined as the second coil spring, the component of the second axial load acting from the second coil spring to the second support member is defined as the second spring load, and the difference between the first spring load and the second spring load at the same door position is defined as the spring load difference, The first coil spring and the second coil spring are The difference in spring load when the door is in the fully closed position is smaller than the difference in spring load when the door is in the fully open position, and When the door position is the fully open position, the second spring load is greater than the first spring load. It is composed of, Vehicle door support device.

2. The first support member and the second support member each further include a brake that mechanically applies rotational resistance to the spindle when the movable housing moves relative to the fixed housing, When the brake of the first support member is defined as the first brake, and the component of the first axial load acting on the first support member from the first brake is defined as the first braking force, and the brake of the second support member is defined as the second brake, and the component of the second axial load acting on the second support member from the second brake is defined as the second braking force, The first brake and the second brake are configured such that the first braking force is greater than the second braking force. A vehicle door support device according to claim 1.

3. The aforementioned brake is A rotating member that rotates integrally with the spindle, A sliding contact member fixed to the fixed housing and slidably in contact with the rotating member, Equipped with, The vehicle door support device according to claim 2.

4. During the automatic opening operation in which the motor displaces the door toward the open position, the first axial load and the second axial load are equal when the door is in the first and second positions. A vehicle door support device according to any one of claims 1 to 3.

5. The spring constant of the first coil spring is greater than the spring constant of the second coil spring. A vehicle door support device according to any one of claims 1 to 3.

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