Vehicle lifting device

Abstract

The objective is to provide a vehicle lifting device that is connected to a vehicle in a manner that allows for raising and lowering, and that makes it easy to load wheeled mobile objects such as wheelchairs, reduces the effort involved in the process, and is also inexpensive to manufacture. [Solution] The system comprises a lifting platform, a connecting mechanism that connects the lifting platform to the chassis so that it can be raised and lowered, and a lifting actuator that raises and lowers the lifting platform. The lifting platform is raised and lowered to include a range between a first height, which is the height along the floor surface inside the vehicle, and a second height, which is the height on the side of the vehicle's contact surface. The connecting mechanism has a tilt mechanism that allows the lifting platform to swing up and down in an adjustable manner, and a link mechanism that connects the lifting platform to the chassis so that it can be raised and lowered via the tilt mechanism. The tilt mechanism switches the lifting platform to a first position at the first height, facing in the direction along the floor surface, and to a second position at the second height, tilted downward toward the rear.

Description

Technical Field

[0001] The present invention relates to a vehicle lifting device that is liftably connected to a vehicle.

Background Art

[0002] A vehicle lifting device is conventionally known, which comprises a lifting platform, a connecting mechanism that liftably connects the lifting platform to the chassis side of a vehicle, a lifting actuator that drives the lifting platform to lift, and a movable slope supported on the rear end side of the lifting platform so as to be swingable up and down; the lifting platform is connected to the chassis side by the connecting mechanism such that its lifting range includes a range between a first height, which is a lifting height along the floor surface in the vehicle, and a second height, which is a lifting height on the ground contact surface side of the vehicle; and the movable slope is configured such that, through its vertical swinging, the posture can be switched between an inclined posture, in which the upper surface of the movable slope is inclined obliquely downward rearward from the upper surface of the lifting platform, and an upright posture, which is erected from the rear end side of the lifting platform.

[0003] According to the vehicle lifting device configured as described above, when the lifting platform is lowered to the second height, switching the movable slope to the inclined posture eliminates or reduces the step on the rear end side of the lifting platform, thereby making it easy to place a moving body equipped with wheels (e.g., a wheelchair) onto the lifting platform, and consequently enabling the moving body to be loaded into the vehicle. However, it is necessary to manually switch the posture of the movable slope, which increases labor.

[0004] To correct this problem, a vehicle lifting device provided with a switching actuator for switching the posture of the movable slope has been known (see, for example, Patent Document 1).

[0005] The vehicle lifting device disclosed in the above document eliminates the need for manual posture switching of the movable slope, thereby reducing labor. However, it requires an additional switching actuator separate from the lifting actuator, which increases the number of parts and leads to higher manufacturing costs.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2005-199868 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to provide a vehicle lifting device that is connected to a vehicle in a manner that allows for vertical movement, and that makes it easy to load a mobile object with wheels, such as a wheelchair, while reducing the effort involved and having low manufacturing costs. [Means for solving the problem]

[0008] To solve the above problems, a vehicle lifting device is provided that is connected to a vehicle so as to be able to move up and down, comprising: a lifting platform; a connecting mechanism that connects the lifting platform to the chassis side of the vehicle so as to be able to move up and down; and a lifting actuator that drives the lifting platform up and down, wherein the lifting platform is connected to the chassis side by the connecting mechanism such that its lifting range includes a range between a first height, which is the lifting height along the floor surface inside the vehicle, and a second height, which is the lifting height on the ground surface side of the vehicle, wherein the connecting mechanism has a tilt mechanism that moves the lifting platform up and down so as to be able to adjust the inclination angle, and a link mechanism that connects the lifting platform to the chassis side so as to be able to move up and down via the tilt mechanism, wherein the tilt mechanism is configured to switch the lifting platform to a first posture at the first height in which its upper surface is oriented in a direction along the floor surface when viewed from the side, and to a second posture at the second height in which its upper surface is inclined downward toward the rear when viewed from the side.

[0009] The tilt mechanism may be configured such that, when switching to the first posture, the upper surface of the lifting platform is parallel to the floor surface inside the vehicle, while when switching to the second posture, the rear end of the lifting platform is in contact with or close to the ground surface of the vehicle. [Effects of the Invention]

[0010] According to the present invention, the lifting platform can be used as a substitute for a movable ramp by switching it to a second position. Furthermore, since the lifting platform is switched to the second position by lowering it to a second height using a lifting actuator, the effort required to get on and off wheeled mobile devices such as wheelchairs is reduced. In addition, there is no need to provide an actuator separate from the lifting actuator, so the configuration is simple and the manufacturing cost is low. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view of a vehicle lifting device to which the present invention is applied. [Figure 2] This is a side view of a vehicle lifting device to which the present invention is applied. [Figure 3] This is an enlarged side view of the main part of a vehicle lifting device. [Figure 4] This is a side view showing a vehicle lifting device in which the lifting platform, held in a first position, has reached the contact height. [Figure 5] This is a side view showing a vehicle lifting device where the lifting platform, held in a first position, has reached the position switching height. [Figure 6] This is a side view showing a vehicle lifting device where the lifting platform has been switched from the first posture to the second posture at the posture switching height. [Modes for carrying out the invention]

[0012] Figures 1 and 2 are plan and side views and a side view of a vehicle lifting device to which the present invention is applied, and Figure 3 is an enlarged side view of the main part of the vehicle lifting device. The vehicle lifting device 1 comprises a lifting platform 2, a connecting mechanism 4 that connects the lifting platform 2 to the chassis 52 side of a vehicle 51 such as a truck or private car (specifically, a support member 3 that is attached and fixed to the chassis 52 and extends integrally downward from the chassis 52) so as to be able to move up and down, and a hydraulic cylinder (lifting actuator) 6 that is retractably provided between the lifting platform 2 and the chassis 52 side and moves the lifting platform 2 up and down.

[0013] The lifting platform 2 comprises a main body 7 and a mounting member 8 integrally attached and fixed to the main body 7, to which the connection mechanism 4 is attached. In the main body 7, a portion of the upper surface excluding the front end portion forms a rectangular shape in plan view and serves as a flat placement surface 7a for placing a moving body having wheels such as a wheelchair, and the front end portion of the upper surface forms an inclined surface 7b inclined downward toward the rear when the placement surface 7a is in a horizontal state. When the placement surface 7a is horizontal, the lower edge 7c of the lifting platform 2 is in a state inclined downward toward the front in a side view.

[0014] The mounting member 8 of the lifting platform 2 is connected to the chassis 52 side by the connection mechanism 4 such that the lifting range of the lifting platform 2 includes a range between a first height, which is a lifting height along the floor surface 53 in the vehicle 51 (in this example, a lifting height identical or substantially identical to the floor surface 53), and a second height, which is a lifting height on the side of the surface G on which the vehicle 51 is grounded (ground contact surface).

[0015] In this example, the first height is the highest position of the lifting range of the lifting platform 2, and the second height is the lowest position of the lifting range of the lifting platform 2. Note that the first height may be set to a position lower than the highest position of the lifting range, and the second height may be set to a position higher than the lowest position of the lifting range.

[0016] The connection mechanism 4 comprises a pair of left and right link mechanisms 9, 9 that connects the lifting platform 2 (specifically, the mounting member 8) to the chassis 52 side so as to be capable of lifting and lowering, and tilt mechanisms 11, 11 provided for each of the link mechanisms 9, 9 that vertically swing the lifting platform 2 to adjust the vertical inclination angle thereof.

[0017] The left and right link mechanisms 9, 9 cooperate and operate in an identical or substantially identical state. Each link mechanism 9 comprises an upper link 13 disposed on the upper side and a lower link 14 disposed on the lower side.

[0018] A rear end of the lower link 14 is attached to and supported by a lower portion of the support member 3 so as to be rotatable vertically, and a front end of the lower link 14 is attached to and supported by a lower portion of the mounting member 8 so as to be rotatable vertically.

[0019] The upper link 13 has a pair of front and rear arms 16 and 17 formed separately. The connecting arm, which is the front arm 16, is linearly formed along the front-rear direction, and the front end portion thereof is supported on the upper portion of the support member 3 so as to be vertically rotatable. The operation arm, which is the rear arm 17, has a wedge shape in a side view, with the front side portion serving as a front piece portion 18 and the rear side portion serving as a rear piece portion 19.

[0020] The upper portion of the attachment member 8 is attached to and supported by the upper portion of the rear piece portion 19 so as to be vertically rotatable. The rear end portion of the connecting arm 16 is connected to and supported at a position obliquely downward behind the portion of the rear piece portion 19 where the attachment member 8 is supported, so as to be vertically rotatable. A pair of front and rear stoppers 18a, 18a against which the upper edge side of the connecting arm 16 abuts are integrally formed on the upper portion of the front piece portion 18.

[0021] With the above-described structure, when the front and rear arms 16 and 17 of the upper link 13 are respectively rotated downward, the overall length of the upper link 13 is shortened; whereas when the front and rear arms 16 and 17 are respectively rotated upward, the overall length of the upper link 13 is lengthened.

[0022] When the connecting arm 16 abuts against the front and rear stoppers 18a, 18a of the operation arm 17, the connecting arm 16 and the operation arm 17 cannot swing further downward, and the link mechanism 9 is switched to a contracted state in which the overall length of the upper link 13 is not further contracted.

[0023] When switching to the contracted state, the distance between the actual or imaginary shafts 13a, 13b serving as fulcrums for vertical rotation at both ends of the upper link 13 is equal to the distance between the shafts 14a, 14b serving as fulcrums for vertical rotation at both ends of the lower link 14, so the link mechanism 9 functions as a parallel link mechanism.

[0024] Incidentally, the coupling mechanism 4 is provided with a locking mechanism (restricting mechanism) 21 that prevents (restricts) the vertical rotation of the connecting portion of the front and rear arms 16 and 17, thereby locking and holding the link mechanism 9 in a retracted state. Here, the state in which the upper link 13 is locked in a retracted state by the locking mechanism 21 is referred to as the locked state (restricting state), while the state in which the lock on the upper link 13 by the locking mechanism 21 is released is referred to as the released state.

[0025] The lifting platform 2 is raised and lowered while being held in a certain position (first position) by the left and right link mechanisms 9, 9 which have been switched to the locked state. When the lifting platform 2 is switched to the first position, its mounting surface 7a (upper surface) is oriented in a direction along the floor surface 53 (specifically, in a direction parallel to the floor surface 53, which in this example is the horizontal direction). On the other hand, when the front and rear arms 16, 17 are rotated upward after being switched to the unlocked state by the lock mechanism 21, the lifting platform 2 is swung downward with the rear axis 14b of the lower link 14 as the pivot point, and is switched to a second position in which its mounting surface 7a is tilted diagonally downward and rearward and its lower edge 7c is oriented in a direction along (parallel to) the ground surface G.

[0026] In other words, the tilt mechanism 11 described above is composed of at least a portion of an upper link 13 that is divided into front and rear sections, and by rotating the operating arm 17 up and down together with the connecting arm 16, the lifting platform 2 is swung up and down to adjust its vertical tilt angle.

[0027] The hydraulic cylinder 6 is mounted at its front end to the lower end of the support member 3 so as to be able to rotate vertically, while its rear end is mounted at the wedge-shaped lower end of the operating arm 17 so as to be able to swing vertically. The pair of upper and lower shafts 13a and 13b on the front side of the link mechanism 9 and the actual or virtual shaft 6a that serves as the pivot point for the vertical rotation of the front end of the hydraulic cylinder 6 are arranged vertically side by side. A ground wheel (ground contact part) 22 that rotates freely around the shaft 6b that serves as the pivot point for the vertical rotation of the front end of the hydraulic cylinder 6 is mounted and supported at the wedge-shaped lower end of the operating arm 17.

[0028] When the link mechanism 9 is switched to the released state by the locking mechanism 21, the hydraulic cylinder 6 extends and retracts to rotate the operating arm 17 up and down. Conversely, when the locking mechanism 21 switches to the locked state, the extension and retraction of the hydraulic cylinder 6 raises and lowers the lifting platform 2, which is held in the first position, relative to the vehicle 51.

[0029] Incidentally, when the lifting platform 2 is raised to the first height, it is preferable that it is switched to the first position in order to facilitate the movement of the moving object from the mounting surface 7a to the floor surface 53 inside the vehicle. Also, when the lifting platform 2 is lowered to the second height, it is preferable that it is switched to the second position in order to facilitate getting on and off between the ground surface G and the mounting surface 7a. Furthermore, while the lifting platform 2 is moving up or down between the first and second heights, it is desirable that it be held in the first position in order to facilitate the stopping of the moving object or person on the mounting surface 7a.

[0030] To achieve this situation, the locking mechanism 21 needs to appropriately switch between a locked state and an unlocked state depending on the height of the lifting platform 2.

[0031] Incidentally, when the lifting platform 2 is raised to the first height and switched to the first position, the two surfaces, the mounting surface 7a and the floor surface 53, are geometrically identical or substantially identical on the same plane (see Figure 3), making it easy to move the moving body from one to the other and vice versa.

[0032] Furthermore, when the lifting platform 2 is lowered to the second height and switched to the second posture, its rear end approaches or contacts the ground surface G, and the mounting surface 7a becomes a slope that continuously slopes forward and upward from the ground surface G, making it easy to move between the ground surface G and the mounting surface 7a.

[0033] Next, the configuration of the locking mechanism 21 will be described in detail based on Figures 2 to 6.

[0034] As shown in Figure 3, the locking mechanism 21 includes an interlocking arm 23 that is supported so as to be able to swing up and down with respect to a shaft 23a located at the rear of the connecting arm 16 of the upper link 13 and protrudes forward from the side of the shaft 23a, a locking member 24 that protrudes downward from the side of the shaft 23a and swings back and forth with respect to the shaft 23a as a pivot, a biasing member 26, and an operating pin 27 that is formed to protrude laterally from the middle part of the lower link 14.

[0035] The interlocking arm 23 has one or more (two in the illustrated example) arc-shaped restricting holes 23b, 23b drilled in it, centered on the axis 23a. Bolts (fixing devices) 28, 28 are inserted through the restricting holes 23b, 23b of the interlocking arm 23 in the left-right direction, respectively, and are detachably fixed to the locking member 24.

[0036] According to this configuration, the relative vertical swing position of the interlocking arm 23 with respect to the locking member 24 is changed within the range in which the bolt 28 moves in an arc shape within the regulating hole 23b through which the bolt 28 is inserted, and when the bolt is fixed, the interlocking arm 23 and the locking member 24 swing together relative to the interlocking arm 23 as a single unit.

[0037] When the link mechanism 9 is in the retracted state, the locking member 24 is swung to the forward position (locked position), causing the tip of the protruding end of the locking member 24 to contact the contact portion 17a, which is a convex portion formed on the lower side of the front edge of the operating arm 17, thereby switching to the locked state described above. On the other hand, when switching to the locked state, the locking member 24 is swung to the rear position (released position), releasing the contact between the locking member and the contact portion 17a, thereby switching to the released state described above.

[0038] The biasing member 26 is a tension spring installed between the operating arm 17 and the locking member 24, and elastically biases the locking mechanism 21 toward the locking state (specifically, elastically biases the locking member 24 toward the rearward swinging state).

[0039] The interlocking arm 23 contacts the operating pin 27 and swings up and down when the lifting platform 2 is raised or lowered to a part of its lifting range. More specifically, the interlocking arm 23 has a first contact portion 23c formed at its lower edge, extending from its front end to the middle, and a second contact portion 23d formed from the middle to the rear. The first contact portion 23c and the second contact portion 23d are shaped like an inverted V when viewed from the side.

[0040] Here, when the lifting platform 2 is lowered from the first height to the second height by retracting the hydraulic cylinder 6, the lifting platform 2 first reaches a contact height, which is a lifting height lower than the first height and higher than the second height, and then reaches a posture switching height, which is a lifting height lower than the contact height and greater than or equal to the second height.

[0041] Figure 4 is a side view showing the state in which the lifting platform held in the first position in a vehicle lifting device has reached the contact height, Figure 5 is a side view showing the state in which the lifting platform held in the first position in a vehicle lifting device has reached the position switching height, and Figure 6 is a side view showing the state in which the lifting platform in a vehicle lifting device has been switched from the first position to the second position at the position switching height.

[0042] When the hydraulic cylinder 6 is extended to its maximum length or a length close to it (a first length) and the lifting height of the lifting platform 2 is at a first height, as shown in Figure 2, the operating pin 27 is positioned in front of the interlocking arm 23 and is not in contact with the operating pin. As a result, the lifting platform 2 is held in the first position by the locked state described above, and its mounting surface 7a is integrally extended rearward from the floor surface 53.

[0043] When the lifting platform 2 is lowered from the first height to the contact height by reducing the hydraulic cylinder 6 from its first length to a predetermined contact length which is shorter than the first length, as shown in Figure 4, the operating pin 27 begins to contact the first contact portion 23c of the interlocking arm 23, but the contact between the locking member 24 and the contact portion 17a of the operating arm 17 is maintained. As a result, the lifting platform 2 is held in the first position by the aforementioned locked state and is positioned diagonally downward and rear of the floor surface 53.

[0044] When the lifting platform 2 is lowered from the contact height to the posture switching height by reducing the hydraulic cylinder 6 from the contact length to a predetermined shorter length, as shown in Figure 5, the contact position between the interlocking arm 23 and the operating pin 27 is displaced from the first contact portion 23c to the second contact portion 23d, and the interlocking arm 23 swings upward during this displacement, causing the locking member 24 to swing forward against the biasing force of the biasing member 26. The forward swing of the locking member 24 releases the contact between the locking member 24 and the contact portion 17a of the operating arm 17, switching from the locked state to the unlocked state, and the grounding wheel 22 makes contact with the grounding surface G.

[0045] Incidentally, the posture switching height is set to a height higher than the second height. For example, it is set to a height of about 100 mm from the ground surface G, so that even if there are irregularities on the setting surface G, the lifting platform 2 will not come into contact with the ground surface G. If such contact prevention measures are unnecessary, the posture switching height and the second height may be set to the same height.

[0046] In this state, the lifting platform 2 is held in the first position by the hydraulic cylinder 6. Furthermore, even when the hydraulic cylinder 6 is extended or retracted between the position switching height and the second length described later, if a load exceeding the lifting capacity of the vehicle lifting device is applied to the rear end of the lifting platform 2, the lifting platform 2 is held in the second position, as the connection position between the connecting arm 16 and the operating arm 17, and the center of gravity of the lifting platform 2 are set accordingly.

[0047] When the lifting platform 2 is lowered to the posture switching height and switched to the first posture, if the hydraulic cylinder 6 is reduced from the posture switching length to a shorter second length, as shown in Figure 6, the lifting platform 2 is lowered to the second height, and due to the contact of the grounding wheels 22 with the grounding surface G, the operating arm 17 is rotated rearward and upward, thereby switching the lifting platform 2 from the first posture to the second posture. In this state, the lifting platform 2 is held in the second posture by the contact of the lower edge 7c of the lifting platform 2 with the grounding surface G, etc. This makes it possible to stably place people or moving objects on the lifting platform 2.

[0048] In other words, when the lifting platform 2 is raised or lowered between the first height and the posture switching height, it is held in the first posture by the action of the tilt mechanism 11 and the locking mechanism 21.

[0049] Furthermore, when the lifting platform 2 is in the process of descending, if its lifting height falls below the posture switching height, the locking mechanism 21 switches it from the locked state to the unlocked state. Conversely, when the lifting platform 2 is in the process of ascending, if its lifting height rises above the posture switching height, the locking mechanism 21 switches it from the unlocked state to the locked state.

[0050] Incidentally, when the lifting platform 2 is in the process of descending, if its height falls below the contact height, the locking mechanism 21 causes the interlocking arm 23 and the operating pin 27 to begin contacting each other. Conversely, when the lifting platform 2 is in the process of ascending, if its height rises above the contact height, the locking mechanism 21 causes the interlocking arm 23 and the operating pin 27 to release from contact.

[0051] Furthermore, when the lifting platform 2 is lowered from the posture switching height to the second height, the tilt mechanism 11 switches it from the first posture to the second posture, while when it is raised from the second height to the posture switching height, the tilt mechanism 11 switches it from the second posture to the first posture.

[0052] By changing the relative vertical swing position of the interlocking arm 23 with respect to the locking member 24 using the means described above, it is possible to appropriately change and adjust the contact length and contact height, as well as the attitude switching length and attitude switching height.

[0053] With the vehicle lifting device configured as described above, it becomes easy to appropriately set the lifting height and orientation of the lifting platform 2 within its lifting range.

[0054] It is also possible to omit the locking mechanism 21. In this case, it is difficult to appropriately set at any point in the lifting range whether the tilt mechanism 11 is activated, but it is possible to switch the lifting platform 2 to the first position at the first height and to the second position at the second height.

[0055] On the other hand, the tilt mechanism 11 can be omitted, in which case the lock mechanism 21 must be configured to switch between a restricted state in which the lifting platform 2 is held in at least a first position and a released state in which it is allowed to swing up and down, and vice versa, and other functions can also be omitted. [Explanation of symbols]

[0056] 1. Vehicle lifting device 2 Elevator 4 Connection mechanism 6. Hydraulic cylinder (lifting actuator) 9 Link mechanism 11 Tilt mechanism 51 vehicles 52 Chassis 53 Floor surface G ground plane

Claims

1. A vehicle lifting device that is connected to a vehicle so as to be able to move up and down, A lifting platform and A coupling mechanism that connects the lifting platform to the vehicle chassis so that it can be raised and lowered, The lifting platform is equipped with a lifting actuator for driving it up and down, The lifting platform is connected to the chassis by the coupling mechanism such that its lifting range includes the range between a first height, which is the lifting height along the floor surface inside the vehicle, and a second height, which is the lifting height on the side of the vehicle's contact surface. The connecting mechanism includes a tilt mechanism that allows the lifting platform to move up and down in an adjustable manner, and a link mechanism that connects the lifting platform to the chassis side via the tilt mechanism so that it can move up and down. The tilt mechanism is configured to switch the lifting platform to a first position at the first height, where its upper surface is oriented in a direction aligned with the floor surface when viewed from the side, and to a second position at the second height, where its upper surface is tilted downward toward the rear when viewed from the side. A vehicle lifting device characterized by the following features.

2. The tilt mechanism is configured such that, when switching to the first position, the upper surface of the lifting platform is parallel to the floor surface inside the vehicle, while when switching to the second position, the rear end of the lifting platform is in contact with or close to the ground surface of the vehicle. The vehicle lifting device according to claim 1.

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