Electric step device

Abstract

To inhibit or prevent a surface temperature of a movable step from being increased excessively regardless of whether the movable step is disposed at an inner position or an outer position.SOLUTION: An electric step device 5 includes: a movable step 6 serving as a footrest member which assists an occupant to get in or off an entrance 2 of a vehicle 1; a drive part 7 for moving the movable step 6 to an inner position of the vehicle 1 and an outer position which protrudes to the vehicle outer side in an area below a vehicle floor surface; and a control unit 9 for controlling operation of the drive part 7. The electric step device 5 further has a coolant jet part 8 which jets a coolant to the movable step 6. The control unit 9 controls operation of the coolant jet part 8 so that the coolant is jetted to the movable step 6 when a stop time of the vehicle 1 is a predetermined value or longer and a surface temperature of the movable step 6 is a predetermined value or higher.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an electric step device. [Background technology]

[0002] For example, Patent Document 1 describes an electric step device that "assists an occupant getting in and out of the vehicle by positioning a movable step at an in-use position below the vehicle floor and outside the vehicle when the occupant is in the vehicle, and stores the movable step in its unused position when the occupant is not in use, the electric step device comprising: a motor that drives a drive unit of the movable step; an operation state detection unit that detects the operation state of the motor; an inclination estimation unit that estimates the inclination state of the vehicle based on the operation state of the motor detected by the operation state detection unit; and a motor output control unit that controls the output of the motor based on the inclination state of the vehicle estimated by the inclination estimation unit." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-100201 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Patent Document 1, if the engine continues to idle while the vehicle is stopped, the exhaust system is not cooled by the wind from the vehicle's movement, and there is a risk that exhaust heat will be transferred to the movable step located near the exhaust system, causing the surface temperature of the movable step to rise.

[0005] In view of the above circumstances, an object of the present invention is to provide an electric step device that can suppress or prevent an excessive rise in the surface temperature of the electric step. [Means for solving the problem]

[0006] The present invention is an electric step device having a movable step as a footrest member assisting occupants in getting on and off at the vehicle's entrance and exit, a drive unit for moving the movable step between an inner position of the vehicle and an outer position below the vehicle floor surface and protruding outside the vehicle, and a control unit for controlling the operation of the drive unit, and further having a coolant injection unit for injecting coolant onto the movable step, wherein the control unit controls the operation of the coolant injection unit to inject coolant onto the movable step when the stopping time is equal to or greater than a predetermined value and the surface temperature of the movable step is equal to or greater than a predetermined value.

[0007] In this configuration, regardless of whether the movable step is located at the inner position or the outer position, when it is predicted that the surface temperature of the movable step will rise excessively due to either exhaust heat or sunlight, the movable step is cooled by injecting a coolant onto the movable step, thereby making it possible to suppress or prevent the surface temperature of the movable step from rising excessively.

[0008] In the above electric step device, the control unit can be configured to perform a first judgment process of determining whether the stopped time has reached a predetermined value or more, a second judgment process of determining whether the surface temperature of the movable step is at a predetermined value or more, a third judgment process of determining whether the elapsed time since the injection of coolant by the coolant injection unit has reached a predetermined value or more, a fourth judgment process of determining whether the vehicle has started to move, an emergency process of operating the coolant injection unit to inject coolant onto the movable step if both the first and second judgment processes are judged to be positive or if the third judgment process is judged to be positive, and a departure process of transitioning to normal processing that manages the operation of the movable step if the fourth judgment process is judged to be positive. Effect of the Invention

[0009] According to the present invention, an electric step device can be provided that can suppress or prevent the surface temperature of the movable step from rising excessively regardless of whether the movable step is positioned in the inner position or the outer position. [Brief description of the drawings]

[0010] [Figure 1] 1A is a perspective view showing one embodiment of a vehicle equipped with an electric step device according to the present invention, and FIG. 1B is a bottom view of the vehicle. [Diagram 2] FIG. 1A is a perspective view of the movable step and the drive unit as viewed from below, and FIG. 1B is a view showing the movable step in an inner position and an outer position. [Diagram 3] 4 is a flowchart for explaining the operation of the electric step device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[0012] An embodiment of the present invention is shown in Figures 1 to 3. In the figures, the front of the vehicle is indicated as Fr, the left side of the vehicle as Lh, and the right side of the vehicle as Rh. As shown in Figure 1(a), in this embodiment, a four-door pickup truck or the like is taken as an example of the vehicle 1, but the present invention can be applied to other vehicle types. This vehicle 1 is provided with entrances 2, for example, at the left front, left rear, right front, and right rear.

[0013] The electric step device 5 is installed in the area between the front and rear wheels at the lower part of the left side (front and rear entrances 2) and the lower part of the right side (front and rear entrances 2) of the vehicle 1, and includes a movable step 6, a drive unit 7, a coolant spray unit 8, a control unit 9, etc. Fig. 1(b) shows only the electric step device 5 installed at the lower part of the left side.

[0014] The movable step 6 is a footrest member for assisting passengers getting on and off at the entrance 2 of the vehicle 1, and is a rectangular plate-like member in a plan view, and is disposed at a distance below the side skirt 4 below the entrance 2 of the vehicle 1 along the front-to-rear direction of the vehicle. The movable step 6 can be formed of, for example, a metal (such as an aluminum alloy), but it can also be formed of, for example, a fiber-reinforced synthetic resin, or a combination of the metal and the fiber-reinforced synthetic resin.

[0015] The movable step 6 can be moved between an inner position indicated by a solid line in Fig. 2(b) and an outer position indicated by a two-dot chain line in Fig. 2(b). The inner position is set at a position below the boarding / alighting entrance 2 and inward from the left or right side of the vehicle 1. The outer position is set at a position where the passenger can easily place their feet when getting on and off at the boarding / alighting entrance 2, that is, a position below the vehicle floor and protruding outward from the left or right side of the vehicle 1.

[0016] The drive unit 7 moves the movable step 6 between the outer position and the inner position as needed, and includes first and second bases 71A, 71B, first and second link units 72A, 72B, a torque rod 73, an electric motor 74, a reduction mechanism 75, etc., as shown in FIG. 2(a).

[0017] The first and second bases 71A, 71B are attached in a suspended state by having their upper portions fixed to two locations spaced apart in the longitudinal direction of the vehicle below the entrance 2 of the vehicle 1. The first and second link units 72A, 72B connect the lower portions of the first and second bases 71A, 71B to two locations spaced apart in the longitudinal direction of the movable step 6, and transmit the rotational power generated by the electric motor 74 and reduced in speed reduction mechanism 75 to the movable step 6. Both the first and second link units 72A, 72B include first and second drive links 76A, 76B, first and second sliders 77A, 77B, and first and second support links 78A, 78B. One end of the first and second drive links 76A, 76B is rotatably supported by the torque rod 73, and the other end is rotatably supported by one end of the first and second sliders 77A, 77B via a pivot pin (not shown). The other ends of the first and second sliders 77A, 77B are attached to the inner side of the movable step 6. One end of the first and second support links 78A, 78B is supported by the first and second bases 71A, 71B via a pivot pin (not shown), and the other end is rotatably supported at the longitudinal center of the first and second sliders 77A, 77B via a pivot pin (not shown). The torque rod 73 receives rotational power generated by an electric motor 74 and reduced in speed by a reduction mechanism 75, and transmits this input rotational power from the first drive link 76A to the second drive link 76B, thereby causing the first and second drive links 76A, 76B to swing synchronously.

[0018] The electric motor 74 and the reduction mechanism 75 are installed on the first base 71 A. An output shaft (not shown) of the reduction mechanism 75 is connected to one end of the torque rod 73.

[0019] In the drive unit 7 configured as described above, the rotational power generated by the electric motor 74 is decelerated by the reduction mechanism 75 and input to the torque rod 73 to rotate the torque rod 73. This rotational motion causes the first and second drive links 76A, 76B to swing synchronously. This swinging motion causes the first and second support links 78A, 78B to swing synchronously while displacing the first and second sliders 77A, 77B synchronously and linearly in the left-right direction of the vehicle. This displacement motion moves the movable step 6 between the inner position and the outer position.

[0020] The coolant spray unit 8 cools the movable step 6 by spraying coolant onto the movable step 6, and although not shown in detail, is equipped with a coolant reservoir, a spray nozzle, a spray pump, etc.

[0021] The cooling liquid reservoir is a tank for storing cooling liquid. The injection nozzles are installed at a plurality of locations at a predetermined pitch in the longitudinal direction of the movable step 6. The injection pump sucks the cooling liquid in the cooling liquid reservoir and pumps it to the injection nozzle. The cooling liquid may be, for example, 20°C ethanol liquid. The amount of injection per time can be appropriately set in consideration of the number of injection nozzles installed.

[0022] The control unit 9 controls the operation of the drive unit 7 and the coolant spray unit 8, and executes normal control and temporary control of the electric step device 5. The control unit 9 controls the operation of the drive unit 7 and the coolant spray unit 8 of each of the left and right electric step devices 5.

[0023] The normal control moves the movable step 6 to the outer position when the left, right, front or rear doors 3 are opened or when an open switch installed on the driver's seat (or rear seat) operation panel (not shown) is operated, while moving the movable step 6 to the inner position when the door 3 is closed or when a close switch installed on the operation panel (not shown) is operated.

[0024] The temporary control operates the coolant injection unit 8 to inject coolant onto the movable step 6 when certain conditions are met, regardless of the position of the movable step 6, and will be described in detail later.

[0025] Although not shown in detail, the control unit 9 is composed of a known ECU (Electronic Control Unit). The ECU includes a central processing unit (CPU), a non-volatile storage device (Read Only Memory: ROM), a temporary storage device (Random Access Memory: RAM), etc. The ROM stores various control programs and maps to be referenced when executing the various control programs. The CPU executes arithmetic processing based on the various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores the results of calculations by the CPU, data input from each sensor, etc.

[0026] Next, temporary control of the electric step device 5 by the control unit 9 will be described with reference to the flowchart of FIG.

[0027] The emergency control shown in the flowchart of Fig. 3 starts after the vehicle 1 has stopped. In short, this emergency control causes the coolant injector 8 to inject coolant onto the movable step 6 when it is predicted that the surface temperature of the movable step 6 will rise excessively, regardless of whether the movable step 6 is positioned at the inner position [see the solid line in Fig. 2(b)] or the outer position [see the two-dot chain line in Fig. 2(b)].

[0028] Specifically, first, in step S1, it is determined whether the stopping time of the vehicle 1 is equal to or longer than a predetermined value. Although not shown in the figure, for example, the time elapsed since the vehicle stopped (referred to as stopping time) can be measured based on the output from a vehicle speed sensor.

[0029] Here, it is checked whether or not passengers get on and off after the vehicle has stopped, and the predetermined value can be set arbitrarily. When the movable step 6 is located at the inner position, the movable step 6 is heated by exhaust heat from the exhaust device 10 [see FIG. 1(b)] regardless of whether the engine is stopped or not, and therefore the surface temperature of the movable step 6 is considered to rise. On the other hand, when the movable step 6 is located at the outer position, the movable step 6 is heated by sunlight, and therefore the surface temperature of the movable step 6 is considered to rise.

[0030] If the determination in step S1 is negative, the process proceeds to step S2, whereas if the determination in step S1 is positive, the process proceeds to step S3.

[0031] In step S2, the control returns to the normal control, and then this flow chart is terminated.

[0032] In step S3, it is determined whether the surface temperature of the movable step 6 is equal to or higher than a predetermined value. Although not shown in the figure, the surface temperature of the movable step 6 can be directly measured based on the output from a temperature sensor installed on the surface of the movable step 6. It is preferable that the predetermined value is appropriately set based on the surface temperature at which the passenger feels uncomfortable when touching the movable step 6.

[0033] If the determination in step S3 is negative, the process proceeds to step S2, but if the determination is positive, the process proceeds to step S4.

[0034] In step S4, the coolant injector 8 injects coolant onto the movable step 6, thereby cooling the movable step 6.

[0035] After step S4, in step S5, it is determined whether or not the elapsed time after the injection of the coolant by the coolant injection unit 8 is equal to or greater than a predetermined value. Although not shown in the figure, the elapsed time can be measured by, for example, an internal timer of the control unit 9. Note that it is preferable to determine the time it takes for the injected coolant to dry in advance through various experiments, and set the predetermined value appropriately based on the experimental results.

[0036] If the determination in step S5 is affirmative, the process returns to step S3. On the other hand, if the determination in step S5 is negative, the process proceeds to step S6.

[0037] In step S6, it is determined whether the vehicle has started to move. Although not shown in the figure, the start of the vehicle's movement can be recognized based on the output from a vehicle speed sensor, for example.

[0038] If the determination in step S6 is affirmative, the process proceeds to step S2, and then ends this flowchart. On the other hand, if the determination in step S6 is negative, the process returns to step S5.

[0039] As described above, in the embodiment to which the present invention is applied, regardless of whether the movable step 6 is positioned at the inner position or the outer position, when it is predicted that the surface temperature of the movable step 6 will rise excessively due to either exhaust heat or sunlight, the movable step 6 is cooled by injecting a cooling liquid onto the movable step 6, thereby making it possible to suppress or prevent the surface temperature of the movable step 6 from rising excessively.

[0040] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the claims and a range equivalent to the claims.

[0041] (1) In the above embodiment, it is possible to eliminate either or both of steps S5 and S6. In this embodiment, the same effects and advantages as those of the above embodiment can be obtained.

[0042] (2) In the above embodiment, the configuration of the drive unit 7 is not particularly limited, and for example, instead of the electric motor 74 and the reduction mechanism 75, a hydraulic or pneumatic linear cylinder can be used to move the movable step 6 between the inner position and the outer position.

[0043] (3) In the above embodiment, the coolant can be the windshield washer fluid installed in the vehicle 1, and the injection pump of the coolant injection unit 8 can be the injection pump for injecting windshield washer fluid installed in the vehicle 1. [Industrial Applicability]

[0044] The present invention can be suitably used in an electric step device equipped in a vehicle. [Explanation of symbols]

[0045] 1 vehicle, 2 boarding / alighting door, 3 door, 5 electric step device, 6 movable step, 7 drive unit, 8 coolant injection unit, 9 control unit.

Claims

[Claim 1] An electric step device having a movable step as a footrest member for assisting a passenger in getting on and off the vehicle at a boarding / alighting entrance, a drive unit for moving the movable step between an inner position of the vehicle and an outer position below a vehicle floor surface and projecting outward from the vehicle, and a control unit for controlling the operation of the drive unit, A cooling liquid injection unit that injects a cooling liquid onto the movable step is further provided. The control unit controls the operation of the cooling liquid injection unit so as to inject cooling liquid onto the movable step when the vehicle stop time is equal to or greater than a predetermined value and the surface temperature of the movable step is equal to or greater than a predetermined value.

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