JP5284600B2 - Table lift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a table lift capable of independently lifting a plurality of tables and lifting them in association with each other while maintaining levelness. <P>SOLUTION: This table lift comprises a plurality of tables for work. Drive sources capable of lifting the tables are installed in the tables, respectively. The table lift is installed in a pit formed under a floor for inspecting and maintaining the lower part of a vehicle. A reflecting plate for reflecting light is installed on at least one of the tables, and a plurality of light emitting/receiving devices emitting light to the reflecting plate and receiving the light reflected by the reflecting plate are vertically disposed at the position of the table adjacent to the table to which the reflecting plate is fitted opposed to the reflecting plate. The table lift also comprises a control means for so controlling the operation of the drive sources that the tables are kept horizontal during the lifting according to the light receiving state of the light emitting/receiving devices. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a table lift, and more specifically, has a plurality of work tables, and is installed in a pit for performing vehicle inspection and maintenance work in an automobile maintenance factory or the like. The present invention relates to a table lift that can be moved up and down.

  Conventionally, in order to inspect and maintain the lower part of a vehicle at an automobile maintenance factory, etc., a work pit has been provided on the floor of the automobile maintenance factory, etc., and this pit improves work efficiency and worker safety. A table lift is installed. The table lift is generally configured to be lifted and lowered. In addition, a pit called a large pit that can be used for inspection and maintenance of large vehicles such as buses and trucks is as large as about 12 m in total length.

  In addition, since the pit has an opening on the floor surface of an automobile maintenance factory or the like, in order to prevent a pedestrian from falling into the opening of the pit when the vehicle is not inspected or maintained and the pit is not used. Then, the table lift is raised to the floor surface to completely cover the pit opening, and the table lift is used as a part of the floor surface.

  When performing inspection and maintenance of the lower part of the vehicle using such pits and table lifts, park the vehicle on the floor of an automobile maintenance shop or the like so that the lower part of the vehicle is located above the pits and work on the table lift. An operator can ride and raise and lower the table according to the height and working posture of the worker, so that work with high work efficiency and high worker safety can be performed.

  For example, when a vehicle is inspected or maintained, another worker may simultaneously perform separate parts such as a front part and a rear part of the vehicle. In such a case, since the height and working posture are different for each worker and the appropriate table height is different, the table is divided into multiple pieces so that the table can be adjusted to the appropriate height for each worker, The height position of each table divided according to the work can be adjusted and used.

However, when performing inspection and maintenance while moving from the front part of the vehicle to the rear part in work such as inspection and maintenance of the vehicle, it is necessary to travel and move a cart including a work tool on the table lift. At this time, the divided table must be kept horizontal so that the division of the table does not hinder the traveling of the carriage.
Therefore, in the past, the height of each divided table was adjusted while visually checking the table, but skilled techniques are necessary to keep the table horizontal by visual inspection, and work to keep the table horizontal The number of people who can be engaged in is limited. In addition, if the table cannot be kept horizontal and there is a step between the tables, in addition to the running of the carriage becoming unstable, the worker walks in a place with a step, so the step is pinched. There is a possibility of falling.

  Therefore, as a table lift for pursuing workability, for example, in Patent Document 1, a table lift is provided in a pit, and the table can be moved up and down from a position about 400 mm higher than a floor of the pit to a position about 400 mm lower. Is composed of a main table and a sub table, and a table lift is disclosed in which the sub table can be raised to the same height as the floor of the work place independently of the main table.

JP-A-6-199495

  However, in the table lift disclosed in Patent Document 1, since there is no table lift over the entire pit, the height of the table lift cannot be adjusted at a free position below the vehicle. Further, in order to move the main table and the sub-table horizontally in conjunction with each other, it is necessary to adjust visually. Furthermore, in order to mechanically configure the single action and the interlock that raises and lowers the main table and the sub table independently, the apparatus becomes large and a great manufacturing cost is required.

  Therefore, in view of the problems of the prior art, the present invention can lift and lower a plurality of tables independently with a simple structure, and can lift and lower a plurality of tables while maintaining the level. The purpose is to provide a table lift.

In order to solve the above-described problems, in the present invention, a plurality of work tables and a drive source capable of moving the tables up and down are provided in each of the plurality of tables, and in a pit provided on the floor for inspection and maintenance of the lower part of the vehicle In the table lift that the operator rides and moves up and down according to the height and working posture of the worker ,
At least one of the plurality of tables is provided with a reflecting plate that reflects light, and the reflecting plate emits light at a position facing the reflecting plate of a table adjacent to the table to which the reflecting plate is attached. A plurality of light emitters / receivers that receive reflected light reflected by the light source are arranged in the vertical direction, and based on the light reception state of the light emitter / receiver, the drive source is operated so as to maintain a horizontal position when the plurality of tables are raised and lowered. There is a control means to control, and furthermore, a foot switch that operates by stepping on the foot is provided on the upper surface of the table, and it is possible to select whether to lift or lower the plurality of tables individually or interlocked and the foot switch, and increase the foot switch for raising the table, the descending foot switch for lowering the table is provided And wherein the door.

  A reflecting plate that reflects light is provided on at least one of the plurality of tables, and the reflecting plate emits light at a position facing the reflecting plate of a table adjacent to the table to which the reflecting plate is attached. By providing the light projecting / receiving device that receives the reflected light, the light receiving state of the light projected from the light projecting / receiving device changes depending on the positional relationship between the height of the reflecting plate and the light projecting / receiving device. For example, when the projector / receiver is located higher than the reflector, the light emitted from the projector / receiver does not reach the reflector and therefore does not reflect, so the projector / receiver cannot detect the received light. When the projector is located at the same height as a part of the reflector, the light projected from the projector / receiver is reflected by the reflector and the received light can be detected by the projector / receiver.

Furthermore, by arranging a plurality of the light emitters / receivers in the vertical direction, the vertical relationship between adjacent tables depends on how many light emitters / receivers detect light reception and which light emitters / receivers detect light reception. I understand.
For example, when two projectors / receivers are arranged in the vertical direction, when the upper projector / receiver detects light reception and the lower projector / receiver does not detect reception, the table provided with the reflector is It can be seen that it is above the table on which the light receiver is provided. Conversely, when the upper light emitter / receiver does not detect light reception and the lower light emitter / receiver detects light reception, the table provided with the light emitter / receiver is above the table provided with the reflector. I understand that.
In addition, when there is one projector / receiver, the vertical position of the projector / reflector and the reflecting plate are shifted so that the received light is not detected, but control becomes impossible. Even if the vertical position of the light emitter / receiver deviates from that of the reflector and no longer receives light, other light emitters / receivers can detect the light and control is possible. Control is possible as long as it is within the distance between the uppermost projector / receiver and the lowermost projector / receiver.

In this way, since the vertical relationship between adjacent tables is known using the reflector and the projector / receiver, the operation of the drive source is controlled by the control means so that the adjacent tables are kept horizontal based on the vertical relationship. By doing so, the table lift can be raised and lowered while the adjacent tables are kept horizontal.
In addition, a foot switch that operates by stepping on the foot is provided on the upper surface of the table, and a single / interlocking foot switch for selecting whether the plurality of tables can be raised or lowered individually or in conjunction with each other, and the table is raised. Since a rising foot switch for lowering the table and a lowering foot switch for lowering the table are provided, it is convenient to operate while maintaining and inspecting the lower part of the vehicle.

  Two projectors / receivers are arranged in the vertical direction, and the control unit controls the drive source only when at least one of the two projectors / receivers receives the reflected light. It is characterized by that.

  Accordingly, since it is sufficient to provide two projectors / receivers, the cost is lower than when three or more projectors / receivers are provided. In addition, when neither the upper or lower light emitter / receiver receives the reflected light, it cannot be determined whether the table provided with the reflector or the table provided with the light emitter / receiver is located on the upper side. It is possible to prevent malfunction of the control means by controlling the drive source only when at least one receives the reflected light.

  The drive source is a hydraulic cylinder, and an oil supply system to the hydraulic cylinder can be opened and closed with an oil supply pump, an oil passage for supplying oil supplied by the oil supply pump to the hydraulic cylinder, and an orifice. A first discharge path through which oil in the oil path can be discharged to the outside of the oil path through an open valve, and oil in the oil path through a valve that is provided separately from the first discharge path and can be opened and closed It has the 2nd discharge path which can discharge | emit out of an oil path.

  As a result, it is not necessary to perform inverter control in order to raise and lower the table lift, and control can be performed with a small oil supply pump, and space saving and initial cost and running cost can be saved.

  Further, when the table is raised, the control means drives the oil supply pump to supply oil to the hydraulic cylinder, raises the table by the hydraulic cylinder, and adjoins based on the light receiving state of the light projector / receiver The valve provided in the 2nd discharge path provided in the oil path which sends oil to the hydraulic cylinder which raises a table which raises a table quicker than a table is open | released, and the raising speed is reduced, It is characterized by the above-mentioned.

  As a result, when the table lift is raised, the oil supply pump that supplies oil to the hydraulic cylinder, which is a drive source for raising each adjacent table, can always be driven. The table lift does not repeatedly rise and stop, and therefore, the plurality of table lifts can be raised while keeping the level without impacting the operator and the carriage on the table lift.

  In addition, when the table is lowered, the control means opens the valve provided in the first discharge passage, lowers the table by discharging oil from the hydraulic cylinder, and based on the light receiving state of the light projecting and receiving device. The valve provided in the second discharge passage provided in the oil passage for lowering the table that descends slower than the adjacent table is opened to increase the lowering speed.

  As a result, when the table lift is lowered, the oil is always discharged from the hydraulic cylinders of the adjacent tables, so the table lift does not repeatedly descend and stop, and therefore impacts workers and carts on the table lift. A plurality of table lifts can be lowered while keeping them horizontal without giving them.

  As described above, according to the present invention, it is possible to lift and lower a plurality of tables independently with a simple structure, and to lift and lower a table while maintaining the level in conjunction with each other. Can be provided.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

FIG. 1 is a longitudinal side view showing a pit and a table lift according to the first embodiment, and FIG. 2 is a longitudinal front view showing the pit and the table lift according to the first embodiment. Hereinafter, the structure of the pits and the table lift will be described with reference to FIGS. 1 and 2, reference numeral 30 denotes a floor surface of a work place such as an automobile factory, and reference numeral 10 denotes a pit formed on the floor surface 30, and table lifts 1 a and 1 b are provided in the pit 10. Further, 12a and 12b are hydraulic cylinders for raising the table lifts 1a and 1b, respectively, and 11a and 11b are hydraulic units for supplying oil to the hydraulic cylinders 12a and 12b, respectively. The table lifts 1a and 1b are raised by supplying oil from the hydraulic units 11a and 11b to the hydraulic cylinders 12a and 12b, and the table lifts 11a and 11b are lowered by discharging oil from the hydraulic cylinders 12a and 12b. Reference numeral 13 denotes a vehicle, which is parked by adjusting the positions of the tires 13a and 13b so that the lower portion of the vehicle is positioned above the pit 10 as shown in FIG.
In the first embodiment, two table lifts 1a and 1b are used. However, the number of table lifts is not limited to two, and any number of table lifts may be used.

  As described above, when the pit 10 and the table lifts 1a and 1b shown in FIGS. 1 and 2 are used to perform maintenance and inspection of the vehicle, the operator rides on the table lift 1a or 1b and the height and work of the worker. The height of the table lift 1a or 1b is adjusted according to the posture, and maintenance and inspection of the lower part of the vehicle 13 are performed.

  FIG. 3 is a top plan view of the table lifts 1a and 1b. Hereinafter, the lifting and lowering operation of the table lift during vehicle maintenance and inspection will be described with reference to FIGS. 1, 2, and 3. The table lift 1a is provided with a single-action / linkage selection foot switch 2, an ascending foot switch 3, and a descending foot switch 4. The switches 2, 3, and 4 are foot switches that are operated by stepping on the feet so that they can be operated while maintaining and checking the lower part of the vehicle in consideration of the convenience of the operator.

  The single-action / linkage selection foot switch 2 is a switch for selecting whether to lift the table lift 1a or 1b alone or to move the table lifts 1a and 1b in conjunction with each other. Either the table lift 1a can be lifted or lowered by pressing the single action / linkage selection foot switch 2, or the table lift 1b can be lifted or lowered while keeping the table lifts 1a and 1b in a horizontal state. Is selected, and the selected state is displayed on the indicator lamp 6. Reference numeral 5 denotes a control panel.

The ascending foot switch 3 is a switch for raising the table lift, and when the ascending foot switch 3 is pressed, oil is supplied from the hydraulic unit to the hydraulic cylinder according to the operation selected by the single action / interlocking selection foot switch 2. The table lift rises.
The lowering foot switch 4 is a switch for lowering the table lift. When the lowering foot switch 4 is pressed, the oil is discharged from the hydraulic cylinder according to the operation selected by the single action / interlocking selection foot switch 2 and the table. Lift goes down.
A mechanism for keeping the table lifts 1a and 1b horizontal during the interlocking operation and an oil supply / discharge system will be described later.

  Further, although not shown, when a wireless remote control switch having the same function as the single-action / interlocking selection foot switch 2, the ascending foot switch 3 and the descending foot switch 4 is used, the operator can select the single-action / interaction selection foot. Even when working away from the switch 2, the ascending foot switch 3 and the descending foot switch 4, the table lift can be raised and lowered without the operator moving, so a wireless remote control switch is also used. It is highly preferred.

  FIG. 4 is an enlarged schematic view of adjacent portions of adjacent table lifts 1a and 1b. A reflection plate 37 is attached to the side surface of the table lift 1a. Further, two projectors and receivers 38 and 39 are attached to the table lift 1b adjacent to the table lift 1a in the vertical direction at a position facing the reflection plate 37. The light projecting / receiving devices 38 and 39 are devices capable of projecting and receiving light, and both the light projecting / receiving devices 38 and 39 are installed so as to project light toward the facing table lift 1a, that is, toward the reflecting plate 37. By providing the reflection plate 37 and the light projecting / receiving devices 38 and 39 in this way, when the table lifts 1a and 1b are at the same height position, all the light projected from the light projecting / receiving devices 38 and 39 is the reflection plate. The light is reflected at 37 and received by the original projector.

  When interlocking is selected by the single action / interaction selection foot switch 2 and the ascending foot switch 3 is further pressed to start the ascending motion, the table lifts 1a and 1b are raised. At this time, even if the table lifts 1a and 1b are lifted at the same hydraulic pressure using the hydraulic cylinders 12a and 12b, the weights of the table lifts 1a and 1b, the weight of the workers on the table lifts 1a and 1b, and other table lifts 1a The lifting speed of the table lifts 1a and 1b varies depending on the weight of the object placed on 1b.

For example, when the ascent speed of the table lift 1a is faster than the ascent speed of the table lift 1b, both the light projecting and receiving devices 38 and 39 receive the reflected light from the reflecting plate 37 at the beginning of the ascent, When the height positional relationship between the reflector 37 and the light emitters / receivers 38 and 39 shifts and the lower light emitter / receiver 39 is positioned below the lowermost part of the reflector 37, the light emitter / receiver 39 detects the reflected light. become unable. Thus, even when the lift speeds of the table lifts 1a and 1b are different, the height positional relationship can be detected by the reflector 37 and the light projecting / receiving devices 38 and 39, and the table lift 1a rising at a high lift speed can be detected. Reduce speed and stay level. The configuration for decelerating will be described later.
In addition, when there is one projector / receiver, the vertical position of the projector / reflector and the reflecting plate are shifted so that light reception is no longer detected, but control becomes impossible, but there are two projectors / receivers (38, 39). ) So that even if the light projecting / receiving device 39 does not detect light reception, the light projecting / receiving device 38 can detect the received light, so that control is possible. What is necessary is just to decelerate the raising speed of the said table lift 1a, and possibility that it will become uncontrollable is very low.

When the ascent speed of the table lift 1b is faster than the ascent speed of the table lift 1a, both the light projecting and receiving devices 38 and 39 receive the reflected light from the reflecting plate 37 at the beginning of the ascent, but as the ascent continues, When the height positions of the reflector 37 and the light emitters / receivers 38 and 39 are shifted and the upper light emitter / receiver 38 is positioned above the top of the reflector 37, the light emitter / receiver 38 cannot detect the reflected light. . Thus, even when the lifting speeds of the table lifts 1a and 1b are different, the height positional relationship can be detected by the reflecting plate 37 and the light projecting and receiving devices 38 and 39, and the rising of the table lift 1b having a high lifting speed. Reduce speed and stay level. The configuration for decelerating will be described later.
In addition, when there is one projector / receiver, the vertical position of the projector / reflector and the reflecting plate are shifted so that light reception is no longer detected, but control becomes impossible, but there are two projectors / receivers (38, 39). ) So that even if the light projecting / receiving device 38 stops detecting light reception, the light projecting / receiving device 39 can detect the light reception, and control is possible. What is necessary is just to decelerate the rising speed of the table lift 1b, and the possibility of being uncontrollable is very low.

  On the other hand, when interlocking is selected by the single action / interlocking switch 2 and the lowering foot switch 4 is further pressed to start the lowering operation, the table lifts 1a and 1b are lowered. At this time, even if the same amount of oil is discharged from the table lifts 1a and 1b and descends, the weight of the table lifts 1a and 1b, the weight of the worker on the table lifts 1a and 1b, and the other on the table lifts 1a and 1b The descending speeds of the table lifts 1a and 1b differ depending on the weight of the object placed on the table.

For example, when the descending speed of the table lift 1a is faster than the descending speed of the table lift 1b, both the light projecting and receiving devices 38 and 39 receive the reflected light from the reflecting plate 37 at the start of the descending, When the height positional relationship between the reflector 37 and the light emitters / receivers 38 and 39 is shifted and the upper light emitter / receiver 38 is positioned above the top of the reflector 37, the light emitter / receiver 38 can detect the reflected light. Disappear. Thus, even when the descending speeds of the table lifts 1a and 1b are different, the height positional relationship can be detected by the reflector 37 and the light projecting and receiving units 38 and 39, and the descending of the table lift 1b having a slow descending speed is possible. Increase speed to stay level. A configuration for increasing the speed will be described later.
In addition, when there is one projector / receiver, the vertical position of the projector / reflector and the reflecting plate are shifted so that light reception is no longer detected, but control becomes impossible, but there are two projectors / receivers (38, 39). ) So that even if the light projecting / receiving device 38 stops detecting light reception, the light projecting / receiving device 39 can detect the light reception, and control is possible. What is necessary is just to increase the descending speed of the table lift 1b, and the possibility of being out of control is very low.

If the lowering speed of the table lift 1b is faster than the lowering speed of the table lift 1a, both the light projecting and receiving devices 38 and 39 receive the reflected light from the reflecting plate 37 at the start of lowering. When the height positions of the reflector 37 and the light emitters / receivers 38 and 39 are shifted and the lower light emitter / receiver 39 is positioned below the lowermost part of the reflector 37, the light emitter / receiver 39 can detect the reflected light. Disappear. Thus, even when the descending speeds of the table lifts 1a and 1b are different, the height positional relationship can be detected by the reflector 37 and the light projecting and receiving units 38 and 39, and the descending of the table lift 1a having a slow descending speed is possible. Increase speed to stay level. A configuration for increasing the speed will be described later.
In addition, when there is one projector / receiver, the vertical position of the projector / reflector and the reflecting plate are shifted so that light reception is no longer detected, but control becomes impossible, but there are two projectors / receivers (38, 39). ) So that even if the light projecting / receiving device 39 does not detect light reception, the light projecting / receiving device 38 can detect the received light, so that control is possible. What is necessary is just to increase the descending speed of the table lift 1a, and the possibility of being uncontrollable is very low.

  5A shows a hydraulic circuit of a hydraulic cylinder 12a that raises and lowers the table lift 1a, and FIG. 5B shows a hydraulic circuit of a hydraulic cylinder 12b that raises and lowers the table lift 1b. First, the configuration of the hydraulic circuit will be described with reference to FIG. When the table lift 1a is raised, in FIG. 5A, the tick valve 27a and the fall prevention are pumped up from the oil tank 21a in which the hydraulic oil is stored in the hydraulic unit 11a by the oil pump 23a operated by the motor 22a. It is supplied to the hydraulic cylinder 12a via the valve 25a. Further, a limiter valve 28a is installed on the output side of the oil pump 23a so as to return to the oil tank 21a, and the hydraulic pressure supplied to the hydraulic cylinder 12a is held at a constant value.

  The fall prevention valve 25a is configured to switch between a communication state and a shut-off state, and communicates when the table lift 1a is at a predetermined lifting speed. However, when the table lift 1a is rapidly lowered due to, for example, pipe leakage, the hydraulic cylinder By shutting off the communication oil passage to 12a, the discharge of the hydraulic oil supplied to the hydraulic cylinder 12a is stopped, the hydraulic oil is held in the hydraulic cylinder 12a, and the table lift 1a is lowered unnecessarily. It is preventing.

Further, an orifice 29a and a lift valve 24a are arranged in series on the downstream side of the fall prevention valve 25a. The lift valve 24a is configured to switch between a communication state and a shut-off state via a check valve. When the table lift 1a is lowered, the lift valve 24a is opened to supply hydraulic oil supplied to the hydraulic cylinder 12a. It returns to the oil tank 21a.
The hydraulic circuit of the hydraulic cylinder 12b that lifts and lowers the table lift 1b shown in FIG. 5B is similarly configured.

Next, the operation of the hydraulic circuit will be described. When the table lift 1a is raised, the motor 22a is turned on to drive the motor at a constant rotation, thereby operating the pump 23a and supplying the discharge pressure oil of the pump 23a to the hydraulic cylinder 12a. The same applies when the table lift 1b is raised.
Further, when interlocking is selected by the single action / interlocking selection foot switch 2, the table lifts 1a and 1b rise in conjunction. When the lift speeds of the table lifts 1a and 1b are different and the height position is deviated by the reflector 37 and the light projecting / receiving devices 38 and 39, the control hydraulic pressure provided in the hydraulic unit 11a or 11b having the higher rising speed is detected. By opening the valve 26a or 26b, the hydraulic pressure of the hydraulic cylinder 12a or 12b can be adjusted to reduce the ascending speed and keep the level.
Accordingly, since the table lifts 1a and 1b can be raised without stopping any rise, there is no impact on the table lift.

When the table lift 1a is lowered, the motor 22a is turned off to stop the pump 23a, and the lift valve 24a is opened to return the hydraulic pressure of the hydraulic cylinder 12a to the oil tank 21a. The same applies when the table lift 1b is lowered.
Further, when interlocking is selected by the single action / interlocking selection foot switch 2, the table lifts 1a and 1b are lowered in conjunction with each other. When the lowering speeds of the table lifts 1a and 1b are different and the height position is deviated by the reflector 37 and the light projecting / receiving devices 38 and 39, the control hydraulic pressure provided in the hydraulic unit 11a or 11b having the lowering lowering speed is detected. The valve 26a or 26b is opened, the hydraulic pressure of the hydraulic cylinder 12a or 12b is adjusted, the descending speed is increased, and the level can be maintained.
Accordingly, since the table lifts 1a and 1b can be lowered without stopping the lowering of the table lifts 1a and 1b, there is no impact on the table lift.

  With a simple structure, each of the plurality of tables can be lifted and lowered independently, and the table can be used as a table lift that can be lifted and lowered while interlocking the plurality of tables.

It is a vertical side view which shows the pit and table lift which concern on Example 1. FIG. It is a vertical front view which shows the pit and table lift which concern on Example 1. FIG. It is a top plan view of table lifts 1a and 1b. It is an expansion schematic of the adjacent part of adjacent table lift 1a and 1b. FIG. 5A shows a hydraulic circuit of a hydraulic cylinder 12a that raises and lowers the table lift 1a, and FIG. 5B shows a hydraulic circuit of a hydraulic cylinder 12b that raises and lowers the table lift 1b.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Table lift 2 Single acting / interlocking selection foot switch 3 Lift foot switch 4 Lower foot switch 10 Pit 11a, 11b Hydraulic unit 12a, 12b Hydraulic cylinder (drive means)
13 Vehicle 23a, 23b Oil pump 24a, 24b Lift valve 26a, 26b Control hydraulic valve 29a, 29b Orifice 30 Floor surface 37 Reflector plate 38, 39 Emitter / receiver

Claims (5)

A plurality of working tables, the a plurality of tables vertically movable driving source tables respectively, are placed in a pit provided in the floor for the servicing of a vehicle bottom, take the operator, working In the table lift that moves up and down according to the height and working posture of the person ,
At least one of the plurality of tables is provided with a reflecting plate that reflects light, and the reflecting plate emits light at a position facing the reflecting plate of a table adjacent to the table to which the reflecting plate is attached. A plurality of projectors / receivers that receive the reflected light reflected by the
Based on the light receiving state of the light projecting and receiving device, provided with a control means for controlling the operation of the drive source so as to maintain a horizontal position when the plurality of tables are raised and lowered,
In addition, a foot switch that operates by stepping on the foot is provided on the upper surface of the table, and a single / interlocking foot switch for selecting whether the plurality of tables can be raised or lowered individually or in conjunction with each other, and the table is raised. A table lift, characterized in that an ascending foot switch for lowering and a lowering foot switch for lowering the table are provided . Two projectors and receivers are arranged in the vertical direction,
2. The table lift according to claim 1, wherein the control means controls the drive source only when at least one of the two projectors / receivers receives the reflected light. The drive source is a hydraulic cylinder;
The oil supply system to the hydraulic cylinder includes an oil supply pump, an oil passage that supplies oil supplied by the oil supply pump to the hydraulic cylinder, and oil in the oil passage through an orifice and an openable / closable valve. A first discharge path that can be discharged outside the oil path, and a second discharge that is provided separately from the first discharge path and that can open and close the oil in the oil path through a valve that can be opened and closed. The table lift according to claim 1, further comprising a path. When the table is raised, the control means
Drive the oil supply pump to supply oil to the hydraulic cylinder, raise the table by the hydraulic cylinder,
Based on the light receiving state of the light emitter / receiver, the valve provided in the second discharge passage provided in the oil passage for sending oil to the hydraulic cylinder that lifts the table that rises faster than the adjacent table is opened, and the rising speed is increased. The table lift according to claim 3, wherein the table lift is lowered. When the table is lowered, the control means
The valve provided in the first discharge path is opened, the table is lowered by discharging the oil in the hydraulic cylinder,
Based on the light receiving state of the light emitter / receiver, the valve provided in the second discharge passage provided in the oil passage for lowering the table that descends slower than the adjacent table is opened to increase the descending speed. The table lift according to claim 3 or 4.

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