JPH08156691A - Step device for vehicle - Google Patents

Abstract

PURPOSE: To make the stroke of an actuator small, improve appearance and attain compactness by connecting an upper stage step and a lower stage step between a service position and a housed position by a link, and connecting the base end part of the actuator to a shaft between longitudinal frames while connecting the tip part to the supporting shaft of the lower stage step through a lever. CONSTITUTION: A first and a second movable steps 5, 6 connected by a link 40 are provided at a pair of longitudinal frames. These steps 5, 6 are rotated upward so as to be placed in a housed position of covering a fixed step 4, and rotated downward so as to be placed in a service position of projecting in stair shape. A shaft is fitted to the longitudinal frames 8, and an air cylinder 20 for rotatory-driving the steps 5, 6 is connected to the shaft 50 and a step 5 side lever 22 respectively at the cylinder base end part and the rod tip part in the vertically rotatable state by a supporting shaft 16. As a result, the air cylinder 20 is assembled to the inside of the longitudinal frames so as to be hidden from the outside view. Appearance is thereby improved, and the stroke quantity of the cylinder 20 can be made small since the lever 22 is formed short.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step device for a vehicle.

[0002]

2. Description of the Related Art In order to improve the ease of getting on and off a large vehicle such as a truck, there are provided two movable steps below the cab (driver's cab), which are normally stored small on the vehicle body side and are placed outside the vehicle when getting on and off the cab. There is one that is made to project like a step (Japanese Utility Model Laid-Open No. 2-115044). In addition, as a technique for improving the steps, Japanese Utility Model Laid-Open No. 59-102551, Japanese Utility Model Laid-Open No. 62-22437 and Japanese Utility Model Laid-Open No. 3-614
The one described in Japanese Patent Publication No. 52 is known.

[0003]

By the way, in such a conventional example, as the driving means for the movable step, the air cylinder is connected at a position away from the support shaft of the step to the outside, so that the stroke required for the opening / closing operation of the step. The amount increases. Therefore, it is difficult to assemble the air cylinder inside the step, and the air cylinder is vertically arranged beside the step. However, this makes the cylinder visible from the outside, and thus the appearance of the vehicle body shaping is not good. Moreover, since a long air cylinder is used, there is a problem in that the boarding / alighting equipment becomes large.

The present invention aims to solve such problems.

[0005]

According to a first aspect of the present invention, a pair of vertical frames which are parallel to each other are installed below a door of a vehicle, and an upper step and a lower step are projected to the outside of the vehicle in a stepwise use position, An operating rod that expands and contracts the actuator at the center of a horizontal shaft that supports the actuators in the vertical direction between the storage positions that stand upright in a column along the side surface, and that connects the base end of the actuator between the vertical frames. The distal end of each of these is rotatably connected around the support shaft of the lower step via a lever, while a link is provided to allow the upper step to follow the rotation of the lower step.

According to a second aspect of the present invention, in the first aspect, the lever is set in a positional relationship in which the step is rotated to the retracted position when the operating rod of the actuator contracts with respect to the support shaft of the lower step.

In the third invention, an air cylinder is provided as the actuator in the first invention or the second invention.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the pipe connecting the air cylinder to the air tank is provided with valve means for stopping the air supply to the air cylinder when the pressure on the air cylinder side falls below a predetermined value.

[0009]

According to the first aspect of the invention, the upper step and the lower step stand upright in a column along the side surface of the vehicle at the storage position and project in a stepwise manner to the outside of the vehicle at the use position. These steps are linked by a link, and when the actuating rod of the actuator expands and contracts, the steps synchronously rotate to the use position and the storage position. In this case, by assembling the actuator inside the step via the shaft and the lever between the vertical frames, the actuator is hidden from the outer area, so that a good appearance can be secured. Moreover, if the lever is formed short, the connecting point of the actuator approaches the supporting shaft on the step side, so that the stroke amount of the actuator can be suppressed small. That is, a short actuator is sufficient, so that the size of the boarding / alighting device can be reduced.

According to the second invention, when the actuator rod contracts, the actuator rotates the lower step and the upper step to the retracted position. Therefore, the actuator is kept in the retracted state except when the passenger gets on and off, so that the mud splashes during traveling or the like. The working rod can be prevented from getting dirty.

According to the third aspect of the invention, when the vehicle-mounted air tank is used as the pressure supply source to the air cylinder, the step driving means can be realized at low cost.

According to the fourth aspect of the invention, the valve means stops the air supply to the cylinder side when the pressure on the cylinder side drops even if air failure or the like occurs in the pipe on the air cylinder side. The pressure can always be kept above a certain value.

[0013]

1 and 2, a fixed step 4 is formed below a door 3 of a cab 2, and a step unit 1 having a first movable step 5 and a second movable step 6 is provided below the fixed step 4. The step unit 1 is shown in FIGS.
Like a pair of parallel vertical frames 7, 8
Is formed and attached to the side surface of the cab 2 via the base 13.

The first movable step 5 is a step panel 9
And a frame 10 for reinforcement on its back surface,
Arms 11 and 12 which stand up from one side edge at a predetermined inclination angle are formed at the central portion and the front end portion of 0. Then, the hinge brackets 1 extending diagonally downward at both lower ends of the base 13
By connecting the arms 11 and 12 to the shafts 4 and 15 via the shaft 16, the first movable step 5 has a use position in which the first movable step 5 horizontally projects to the side of the cab 2, and the step surface is the cab 2.
It is rotatably supported in the vertical direction between the storage position along the side surface.

The arm 12 is extended in a dogleg shape, and a stopper rubber 18 is attached to the tip of the arm 12 so as to abut a central rear surface of a stopper bracket 17 described later at a use position. A pipe 19 forming an axial hole of the shaft 16 is connected between the arms 11 and 12, and the shaft 16 is coupled to the hinge brackets 14 and 15 at both end portions passing through the pipe 19. Air cylinder 20 and return spring 21
In order to attach the clevis, a clevis-shaped lever 22 and a hook-equipped lever 23 are formed at the center of the outer circumference of the pipe 19.

The second movable step 6 is provided with a step panel 30 and a reinforcing frame body 31 on the back surface thereof like the first movable step 5, and both end portions of the frame body 31 have a predetermined inclination angle from one side edge. Arms 32 and 33 that stand upright are formed, and by using the shafts 36 to connect the arms 32 and 33 to hinge brackets 34a and 34b projecting to the side of the cab 2 at an intermediate portion of the base 13, a horizontal step surface can be used. It is rotatably supported in the vertical direction between the position and the standing storage position.

The stopper rubber 3 which abuts against both end surfaces of the stopper bracket 17 at the use position of the arms 32 and 33.
5a and 35b are attached, and as shown in FIG. 9, a stopper function for restricting the first movable step 5 to the storage position is also added to these rubbers 35a and 35b. The first
When the movable step 5 comes into contact with the stopper rubbers 35a and 35b, the second movable step 6 is also restricted to the storage position via a link 40 described later. Reference numeral 38 is a pipe that forms a shaft hole of the shaft 36 in the hinge brackets 34 and 35, and the shaft 36 is connected to the arms 32 and 33 at both end portions passing through the pipe 38.

In order to rotate the first movable step 5 and the second movable step 6 synchronously, a link 40 connecting them is provided. Then, when the movable steps 5 and 6 rotate the first movable step 5 upward, the second movable step 6 follows the same and rotates upward, and the second movable step 6 moves to the cab 2. When the first movable step 5 stands upright in a column along the side surface of the cab 2 and the second movable step 6 in the storage position that covers the fixed step 4, the first movable step 5 is rotated downward to make the second movable step. The step 6 follows this and rotates downward, and the second movable step 6 moves to the first movable step 5 at the use position where the second movable step 6 overhangs horizontally.
Is larger than the second movable step 6 and protrudes in a staircase shape.

The link 40 is connected to the outer edges away from the shafts 16 and 36 by the shafts 41 and 42 at both ends at the front ends of the steps 5 and 6 which do not interfere with getting in and out of the vehicle. It is stored so as to overlap these front end faces. Covers 45 and 46, which form a part of the vehicle body shaping, are attached to the back surfaces of the first movable step 5 and the second movable step 6 at the retracted position, respectively. The link 47 is also provided with a cover 47 for providing a sense of continuity in vehicle body shaping.

The stopper bracket 17 is formed of a substantially U-shaped member having flanges on both ends, is joined to the base 13 at a predetermined position by the flanges, and is inserted through the stopper rubbers 18, 35a, 35b when getting on and off the cab 2. The load received by the movable step 5 and the second movable step 6 is supported. In this case, since the load is applied to the central rear surface and both end surfaces of the stopper bracket 17, the strength is more advantageous than the case where the load is always applied to only one side surface.

In order to mount the air cylinder 20 inside the base 13, the vertical frames 7 and 8 have brackets 49a,
A shaft 50 that rotatably supports the clevis 60 at the base end of the cylinder is attached via 49b. Since the return spring 21 is attached inside the base 13,
The vertical frame 8 is provided with a screw portion 53 that supports the screw rod 52 so as to be capable of advancing and retracting toward the pipe 19 on the step 5 side via the bracket 51, and a hook 52a is formed at the tip end portion of the screw rod 52.

The air cylinder 20 drives the steps 5 and 6 to rotate, and the shaft 50 on the base side and the lever 2 on the step 5 side are respectively provided at the cylinder base end and the rod tip end.
It is connected to 2 by a pin which is freely rotatable in the vertical direction. The return spring 21 is engaged at both ends with a screw rod 52 on the base 13 side and a lever 23 on the step 5 side,
The steps 5 and 6 are urged to the storage position.

By assembling the air cylinder 20 and the return spring 21 inside the base 13, these are hidden from the outside, so that the appearance of the cab is improved. Further, by forming the lever 22 to be short, the connecting point with the air cylinder 20 approaches the shaft 16 of step 5, so that the stroke amount of the cylinder 20 can be suppressed to be small.
That is, since the short air cylinder 20 is sufficient, the getting on / off device can be advantageously downsized (see FIG. 10). Air cylinder 2
With respect to No. 1, since the steps 5 and 6 are rotated to the retracted position by the contraction operation of the rod as will be described later, the rod is not contaminated due to splattering during running.

Then, the first movable step 5 and the second movable step
The movable step 6 of the air cylinder 20 is
When the air cylinder 20 extends, it horizontally projects to the outside of the cab 2 to form a stepwise three-step step including the fixing step 4 of the cab 2, while when the air cylinder 20 contracts, the cab 2 is stored in columns as shown in FIG. The covers 45 to 47 form a vehicle body below the door 3. Therefore, the ability to get on and off the cab 2 is improved, and the appearance and aerodynamic performance when the step is stored can be improved.

Since steps 5 and 6 do not overlap each other in the vehicle width direction when stored, but stand upright in a column along the side surface of the cab 2, the layout in the vehicle width direction can be made small. Since the second movable step 6 covers the fixed step 4 of the cab 2 at the storage position, snow, mud, etc. do not adhere to the fixed step 4 during traveling. When the door 3 is opened, the second movable step 6 covering the side edge of the fixed step 4 can be seen from inside the cab 2, so that it can be easily confirmed whether or not the steps 5 and 6 are in the use position. In FIG. 3, 55 is a valve unit that controls the drive of the air cylinder 20, and is attached to the base 13 via a bracket 56.

FIG. 12 shows a circuit configuration of the air cylinder 20. Reference numeral 65 is a piston that divides the inside of the cylinder into two chambers 66 and 67. These chambers 66 and 67 are throttle valves 68 and 69 and a magnet valve, respectively. It is connected to the air tank 72 via 70 and 71. Magnet valve 70,
The supply position 71 and the exhaust position 71 are provided in an inverse relationship with each other, and are wired to the power source through one switch 74. When the magnet valve 71 is switched to the exhaust position and the magnet valve 70 is switched to the supply position when the switch 74 is turned off, the piston 65 operates toward the rod contraction side while receiving the air from the air tank 72 to the chamber 66 and discharging the air from the chamber 67. On the other hand, when the magnet valve 71 is switched to the supply position and the magnet valve 70 is switched to the exhaust position by turning on the switch 74, the supply of air and the exhaust are reversed, so that the piston 65 operates toward the rod extension side. There is.

When an air failure occurs in the drive circuit of the air cylinder 20, the pressure in the air tank 72 is released. Therefore, the pressure in the air tank 72 is set to a predetermined value (for example, the normal value of the supply pressure is 5.5 to 8.5 as a means for preventing it). In order to maintain a predetermined value of 4.5 kg / cm ² or more as kg / cm ² , a protection valve 73 that controls the air supply to the cylinder 20 side is provided. In addition, even if a failure occurs in which the magnet valve 71 is fixed at the supply position, step 5,
A manual valve 74 for evacuating the air in the chamber 67 is added so that the storage of 6 can be performed.

In order to control the operation of the air cylinder 20 (switch on / off), a control unit 80 as shown in FIG. 13 is provided. In this case, in addition to the ignition switch 81 of the engine, the neutral switch 82 of the transmission, the tilt stopper switch 83 and the tilt lock switch 84 of the cab, and the door as conditions for permitting the rotation to the use position in steps 5 and 6. Door switch 85 for detecting opening / closing of 3 (turning on / off the room lamp in conjunction with opening / closing of door 3), and step switch 86 for confirming storage of steps 5 and 6
(See FIG. 11), a door opening switch 87 is provided which is activated when the door 3 is opened more than the angular position corresponding to the outermost step of the use position.

The control unit 80 includes an IGN system determination unit 88 and a CAB system determination unit 89, and a determination unit 90 that determines whether or not the stopper opening condition is satisfied by adding door side conditions to them.
Based on the result, a control signal output section 91 for turning on / off the step solenoid 96 (which constitutes a switch relay of the magnet valves 70, 71) and an alarm determination section 9
4 and an output unit 95, an output unit 93 for controlling the cabult and a judgment unit 92 which also has a control function thereof. In addition, 99 is a power supply part of the control unit 80, 97 is a buzzer for warning the storage failure of steps 5 and 6, and 98 is a stroke switch of the tilt cylinder.

FIG. 14 is a flow chart for explaining the control contents of the control unit 80. The cab mount is locked from the signals of the tilt stopper switch 83 and the tilt lock switch 84, the door switch 85 is turned on,
When the door opening switch 87 is on, the conditions of the ignition switch 81 and the neutral switch 82 are satisfied (when the ignition switch 81 is off or an accessory, it is not related to the neutral switch 82, but the ignition switch 81 is on. In this case, when the neutral switch 82 is turned on to determine whether the condition is satisfied), a control signal for rotating steps 5 and 6 to the use position is output (process numbers 1 to 6). If any one of these conditions is not satisfied, a control signal for returning steps 5 and 6 to the storage position is output, the storage is checked by the step switch 86, and the buzzer 9 is returned if steps 5 and 6 do not return.
7 is activated (process number 8 to 10).

According to this, when the engine is stopped while the cab 2 is tilt-locked or the neutral setting of the transmission is performed, steps 5 and 6 are automatically performed between the use position and the storage position by opening and closing the door 3. Open and close (rotate). When the door 3 is opened, the steps 5 and 6 of turning to the use position may hit an external obstacle (wall, fence, etc.), but the addition of the door opening switch 87 causes the step 5 to the outermost position of the use position. If the door is not opened wider than the corresponding angular position, steps 5 and 6 do not project to the use position, and therefore safety against obstacles outside the door can be secured. Even if the door open / close switch 87 fails, steps 5 and 6 are stored when the door 3 is closed and the door switch 85 is turned off.

As for the door opening switch 87, the same inexpensive push-pull switch as the door switch 85 is adopted, and in order to expand the off range of the switch 87 with respect to the door opening, the switch trigger 100 as shown in FIGS.
In combination with the door hinge 106, the door hinge 106 is arranged near the rotation center 101 (hinge center). Reference numeral 102 denotes a bracket to which the switch 87 is replaceably mounted on the cab 2 side, and a trigger lever 103 is supported by a base end portion of a front surface of the bracket 102 facing the tip of the switch 87 so as to be freely rotatable in the opening / closing direction of the door 3. In addition, the trigger lever 1 is attached to the door panel 3a.
When the trigger protrusion 104 hanging on the front end side of 03 is adjustably attached through the long hole, the trigger lever 103 is pushed within the predetermined opening of the door 3 to turn off the switch 87, and the door 3 opens more than the predetermined opening. The switch 87 is opened (turned on). In addition, the spring 1 for urging the trigger lever 103 to the bracket 102 in the opening direction of the door 3
05 is assembled.

[0033]

According to the first aspect of the present invention, a pair of vertical frames which are parallel to each other are attached to the lower side of the door of a vehicle, and the upper step and the lower step are projected to the outside of the vehicle in a stepwise manner, and on the side surface of the vehicle. Along with the storage position that stands upright in the vertical direction, each of which supports the actuator in a vertically rotatable manner, and the base end of the actuator is attached to the center of the horizontal shaft that connects the vertical frames to the tip of the actuator rod that expands and contracts. While the parts are connected via a lever to freely rotate around the support shaft of the lower step, the actuator has a link that allows the upper step to follow the rotation of the lower step. Since it is assembled inside the and hidden from the outside,
A good appearance can be secured. Further, if the lever is formed short, the connecting point of the actuator approaches the support shaft on the step side, so that the stroke amount of the actuator can be suppressed small. That is, it is possible to effectively reduce the size of the boarding / alighting device.

According to the second aspect of the invention, the lever is set in a positional relationship in which the step is rotated to the retracted position when the operating rod of the actuator contracts with respect to the support shaft of the lower step, so that the actuator is actuated when the step is retracted. Since the rod is not exposed, it is possible to prevent the rod from becoming dirty due to mud splashing while traveling.

According to the third invention, since the air cylinder is used as the actuator, the step driving means can be realized at low cost by using the vehicle-mounted air tank as the pressure supply source to the air cylinder.

According to the fourth aspect of the invention, the pipe for connecting the air cylinder to the air tank is provided with the valve means for stopping the air supply to the air cylinder when the pressure on the air cylinder side becomes lower than the predetermined value. Even if an air failure occurs in the side pipe, the pressure on the air tank side can be maintained at a predetermined value or higher.

[Brief description of drawings]

FIG. 1 is a perspective view of a step used state.

FIG. 2 is a perspective view of a step retracted state.

FIG. 3 is an exploded perspective view of a step unit.

FIG. 4 is an exploded perspective view of a first movable step.

FIG. 5 is an exploded perspective view of a second movable step.

FIG. 6 is a perspective view of a link and a cover.

FIG. 7 is a cross-sectional configuration diagram including an operation state description of a step unit.

FIG. 8 is a schematic perspective view of a step unit.

FIG. 9 is an operation explanatory diagram of steps.

FIG. 10 is a layout explanatory view of an air cylinder and the like.

FIG. 11 is an operation explanatory diagram of steps.

FIG. 12 is a drive circuit diagram of an air cylinder.

FIG. 13 is a configuration diagram of a step control system.

FIG. 14 is a flowchart illustrating the control content of the control unit.

FIG. 15 is an assembly state diagram of a door opening switch.

FIG. 16 is an operation explanatory view of a switch trigger.

[Explanation of symbols]

1 step unit 2 cab 3 door 4 fixed step 5 first movable step 6 second movable step 11, 12 first movable step arm 14, 15 first movable step hinge bracket 16 first movable step Shaft 17 Stopper bracket 18 First movable step stopper rubber 20 Air cylinder 21 Return spring 22 Air cylinder connecting lever 23 Return spring locking lever 32, 33 Second movable step arm 34a, 34b Second Movable step hinge brackets 35a, 35b Second movable step stopper rubber 36 Second movable step shaft 40 Link 41, 42 Link shaft 45, 46 Step cover 47 Link cover 50 Air cylinder supporting shaft 52 Return strip Screw rod for pulling locking 55 Valve unit 70,71 Magnet valve 73 Protection valve 80 Control unit 81 Ignition switch 82 Neutral switch 83 Tilt stopper switch 84 Tilt lock switch 85 Door switch 86 Step step 87 Door opening switch 96 Step solenoid 97 Alarm buzzer 100 switch trigger

Claims (4)

[Claims] 1. A pair of vertical frames mounted parallel to a lower side of a door of a vehicle, a use position in which an upper step and a lower step are projected in a stepwise manner to the outside of the vehicle, and a storage position which stands upright in a column along a side surface of the vehicle. Between the vertical frames, the base end of the actuator is connected to the center of a horizontal shaft connecting the vertical frames, and the tip of the actuator rod that expands and contracts is used to lower the step through the lever. A step device for a vehicle, which is provided with a link that allows the upper step and the lower step to follow the rotation of the lower step while being rotatably connected to each other around the support shaft of the vehicle. 2. The step device according to claim 1, wherein the lever is set to have a positional relationship of rotating the step to the retracted position when the operating rod of the actuator contracts with respect to the support shaft of the lower step. 3. The step device according to claim 1, wherein an air cylinder is used as the actuator. 4. The pipe connecting the air cylinder to the air tank is provided with valve means for stopping the air supply to the air cylinder when the pressure on the air cylinder side falls below a predetermined value. Step equipment.