JPS62111896A - Elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a four-way descending device for moving a folding platform downward by -1.

[Conventional technology and its problems 1 Conventionally, for construction work, civil engineering work, painting work, etc. at high places, a landing platform loaded with workers and luggage has been operated using hydraulics etc.
The next move is to lower the stomach and lower the neck. This 4
The lowering device has a plurality of link mechanisms vertically arranged in which a pair of arms are rotatably pivoted at the center, and adjacent link mechanisms are rotatably connected at the end of each arm to form a pantograph. A hydraulic cylinder with a press yaw that expands and contracts stepwise in the longitudinal direction is installed between one arm and the other 77 arms, and the hydraulic cylinder is equipped with a J: Avoid extending and contracting the 4-lowering mechanism! ? 1 + l'r: Move the storage platform attached to the most part of the lowering mechanism 1
! :It is something that

In this evacuation device, if the back evacuation platform continues to be lowered or lowered with items exceeding the maximum carrying capacity Φ loaded, there is a risk that stress will be applied to each part of the elevating device, resulting in damage and an accident. was there.

Therefore, it is necessary to provide a safety mechanism that detects the load applied to the platform and stops the platform if the load exceeds a predetermined value. One way to detect this load is to detect the hydraulic pressure value of the hydraulic cylinder, but in the case of a telescopic hydraulic cylinder that expands and contracts in stages, even if a constant load is applied, the hydraulic cylinder's hydraulic pressure It is difficult to detect the load applied to the lifting platform because it differs for each expansion/contraction stage, and therefore, this lifting device was not provided with the above-mentioned safety nttR.

The object of the present invention is to provide an R-lowering device using a telescopic fluid pressure cylinder, which detects the load applied to the platform no matter what height the platform is at, and in case of overload, lifts or lowers the platform. An object of the present invention is to provide a lifting device equipped with a safety mechanism for stopping the platform.

[Tm1 for solving the problem In order to solve the above problem, the lifting device of the present invention is constructed as follows. That is, in the lifting device using the telescopic fluid pressure cylinder as described above, a detection device is provided to detect the fluid pressure of the fluid pressure cylinder at each expansion/contraction stage of the telescopic fluid pressure cylinder, and A control device is provided to stop the lifting platform when each fluid pressure exceeds a set value set for each expansion/contraction stage.

It is preferable that the safety structure consisting of the detection device and the control device works both when the lifting platform is raised and lowered. According to C
Even if it is configured to work in the case of 1% 1-tJ, will it still work? (Even if you configure it so that it works for J, it doesn't work for J.

[Function] - The telescope type fluid pressure cylinder described above has another screw 1 which is slidably installed inside the screw 1 which is movably inserted in the cylinder tube. For example, a two-stage type has two pistons, and a three-stage type has three screws.In other words, the number of stages in this hydraulic cylinder is The piston expands and contracts by sliding in stages against the cylinder tip.

In this telescopic fluid pressure cylinder, a higher pressure is applied when the second stage piston, that is, the inner piston, is extended than when the first stage piston, that is, the outer piston, is extended. Because you need it,
When the pistons extend, they extend from the outer pistons first.

Conversely, when the piston is compressed by applying a load from the outside, the piston contracts from the inside in order, and the fluid pressure within the fluid pressure cylinder differs depending on the operating stage of each screw 1 to n.

In the W-18m device of the present invention, the permissible value is determined for each operation stage of each screw 1 to 1 based on the fluid pressure value of the fluid pressure cylinder when the maximum load is applied to the lifting platform at each piston operation stage. The fluid pressure to be used is set to A3,
For each piston actuation stage, if the fluid pressure in the hydraulic cylinder exceeds the setting 11r1 for that stage, W
-11'One unit is stopped.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 shows an embodiment of the present invention with arm M = 14, where 1 is a car body of 1 to 100mm, and this car body 1 is provided with an outrigger 2 for fixing and lifting it. ing.

On the upper surface of the vehicle body 1, a four-way lowering mechanism 3 of a ground type is arranged, and at the upper end thereof, a J8 soundproofing mechanism 5 for carrying workers and cargo is installed. A handrail 6 is provided around the upper surface of the elevator platform 5.

This scissor type elevating ta eM 3 has a link mechanism 8 which is a pair of arms 7a and 7b rotatably connected in the center to form an X-shape.
are arranged in parallel at a predetermined interval on the left and right (direction perpendicular to the plane of the paper), and arms 7a, 7a and 7b arranged on the left and right.
, 7b are connected to each other via a connecting shaft 9, and these are stacked up in four stages in the vertical direction. -h'), each arm 7a, 7aJ5 and 7
The ends of b and 7b are rotatably connected to each other by the connecting shaft 9. Further, the end of one of the lowermost arms 7a and 7b is connected to the vehicle body 1 by a pin 10, and a roller 11 is attached to the end of the other arm 7b.

Further, the end of one arm 1b of the uppermost arms 7a and 7b is connected to the lowering platform 5 by a bin 12, and a roller 13 is attached to the end of the other arm 7a. Roughly speaking, between the arm 7a of the link mechanism 8 at the F-most part and the arm 78 of the link mechanism 8 above it, and the link mechanism 8 at the top
A telescopic hydraulic cylinder 30 is disposed between the arm 7b of the link mechanism 8 and the arm 7b of the link mechanism 8 below the arm 7b. This hydraulic cylinder 30 has a cylinder tube 3O
Install the second stage screw 1 inside the first stage piston 30b in a.
It is equipped with a hem 30C and can be expanded and contracted in two stages. zu-4t;i)j, this hydraulic cylinder 30
If it stretches, first screw the screws 1 to 301 of the 1st stage t-1.
1/l<extends, then the piston 30C of the second stage [1] extends. Also, when this hydraulic cylinder 30 contracts, first the second stage screw 30c contracts, then the first stage piston 30b contracts, and the first piston 30b of this hydraulic cylinder 30 is parallel to the The rack is held by a support rod 14 that is passed between the arms 7a, 7a or 7b, 7b of the left and right arms 7a, and the lower end is connected to the upper pair of arms 7a.
, 7a or between 7b and 7b.
is held by. Further, a hydraulic device 20 consisting of a hydraulic pump or the like that generates hydraulic pressure is fixed on the vehicle body 1, and is connected to a hydraulic cylinder 30 via a hydraulic control circuit to be described later. By expanding and contracting the hydraulic cylinder 30 by this hydraulic device 620, the Y group 1 structure 3 is expanded and contracted in a pantograph style V -C, and the lifting platform 5 attached to the part is moved -1-t! )-can be done.

FIG. 4 is a graph showing changes in the oil pressure of the &I+ pressure cylinder 30 depending on the height when an object with the maximum load is placed on the top of the lifting platform 5. 1 at a position lower than height 1
The piston 30b in the first stage works, and the piston 30c in the second stage works at a position higher than the height 11.

Further, a limit switch 1-8 (
(not shown in FIG. 1) are attached, and the limit 1 to the switch LS are actuated by the arm 7a that can fall down when the lifting platform 5 is lowered to the height H.

In addition, a bracket is installed to adjust the operating position of Limit 1 to Switch LS.

This limit switch LS is connected to a safety mechanism described below.

FIG. 2 shows the hydraulic control circuit. 25 is a hydraulic pump, 31 is a directional control valve, and 32 is a lift valve.

This directional control valve 31 is normally kept in one state shown in the figure by a spring, that is, the state in which the discharge port of the hydraulic pump 25 is connected to the pipe line leading to the tank 45, and this is achieved by energizing the solenoid. 2J is switched so that it is connected to the conduit leading to the rift 1 hebal 132. The rifts 1 to 32 are composed of a sequence valve 33, a check valve 34, a solenoid switching valve 35, and a variable throttle valve 36. The solenoid switching valve 35 is normally in the state shown in FIG. 2, that is, the state in which the check valve is connected to the pipe line, by a spring, and is switched so that the pipe line is conductive by excitation of the solenoid. . Further, 37 is a flow rate regulating valve with a check valve, and 40 and 41 are safety valves. Further, PSII and 1) Sl- are an upper pressure switch and an F section pressure switch, respectively, which are activated when the oil pressure of the hydraulic cylinder 30 becomes one step above the F91 constant pressure. The upper pressure switch P S I+ is activated when the hydraulic pressure of the hydraulic cylinder 30 exceeds the pH value, and the 1-r switch for the upper part P S I+ is activated.
L is activated when the oil pressure of the hydraulic cylinder 30 becomes 11- or more (see FIG. 1). 44 is an emergency drop valve. In addition, each of the TOS units listed in 1- are connected by pipes.

First, when lifting the platform 5, the directional control valve 31 is switched to the left in the figure, and the oil is supplied by the hydraulic pump 25 to the check valve 34, flow rate adjustment valve 37, and safety valve 40.4.1. and is sent to the hydraulic cylinder 30.

At this time, when the directional control valve 31 is switched to its original state (the state shown in the figure), the lifting platform 5 stops rising. and,
When lowering the lifting platform 5, the solenoid switching valve 35 is switched to the left in the figure, and the oil in the hydraulic cylinder 30 is transferred to the safety valve 40, 41, the flow rate adjustment valve 37 with a check valve, and the throttle valve 36.
, and is sent to the tank 45 through the solenoid switching valve 35. At this time, when the solenoid switching valve 35 is switched to the original state (the state shown in the figure), the return of oil from the hydraulic cylinder 30 to the tank 45 is stopped by the check valve of the solenoid switching valve 35, and the lowering of the elevator platform 5 is stopped. Stop.

Next, an electric circuit for controlling the directional switching valve 31 and the solenoid switching valve 35 will be explained using FIG.

1-S is the aforementioned limit switch, PBu is an upper push button switch, and PBd is a lower push button switch. P S H is the upper pressure switch, and PSI is the lower pressure switch. RLl, Rd, and CX are relays, which respectively connect the electromagnetic coil RU, the contact R111, and the electric current R11.
It is composed of a d contact Rd1, an N magnetic coil Cx, a contact CX1, and a 'C'.

Further, lu and ld are a 10Wf solenoid and a lowering solenoid, respectively. , ten-purpose solenoid 1-u
6 is for switching the directional switching valve 31 to send oil from the pump 25 to the cylinder 30.

Next, Takeda of this electric circuit will be explained.

Climb up the elevator platform 5! When pressing the button switch P Ru for one stomach, the electric current RU is energized and the contact R (11 is closed. Therefore, the raising solenoid 1.u is activated and the direction is changed. The valve 31 is switched to the left in the drawing, oil is sent to the hydraulic cylinder 30, and the 4 o'clock position 5 is raised.

When lowering the elevator platform 5, when the lowering pushbutton switch PBd is pressed, the electromagnetic coil Rd is energized and the contact Rd1 is closed. Then, the lowering solenoid L d
is energized, the solenoid switching valve 35 is switched to the left in the figure, and the oil in the hydraulic cylinder 30 is returned to the tank 45.
The lifting platform 5 descends.

When the lifting platform 5 is at a position lower than the height T1, the limit switch S is closed, and in this position, when the load applied to the lifting platform 5 exceeds a predetermined value, the hydraulic pressure of the hydraulic cylinder 30 is reduced. exceeds a predetermined value P1-,
Lower pressure switch PSI- is activated. Then, the electromagnetic coil Cx is energized, contact Cx1 is opened, and neither the ascending solenoid LU nor the descending solenoid L-d is energized, and the ascending button switch PBu or the descending button switch PBd is activated. Even if it is pushed, the lifting platform 5 will neither ascend nor descend.

In addition, if the lifting platform 5 is located at a position higher than the height H,
The limit switch LS is open and in this position, the TE? When the load applied to the platform exceeds a predetermined value and the hydraulic pressure of the hydraulic cylinder 30 exceeds a predetermined value []11, the soil pressure switch P S
I+ creates iFI+-i 1, so as above, upper back solenoid 1-[1 also works solenoid L d
4i' is also energized, the pushbutton switch PBusl for the upper field or the pushbutton switch PB for the lowering
Even if d is pressed, the lifting platform 5 will neither rise nor fall -b.

Thus, in this embodiment, a hydraulic cylinder is used as the fluid pressure cylinder. A pressure switch is used as a detection device, and a hydraulic circuit shown in FIG. 2 and an electric circuit shown in FIG. 3 are used as a control device.
These constitute the safety mechanism.

[Effects of the Invention] As described above, the adhesive of the present invention? The descending device is equipped with a safety mechanism that detects the load applied to the platform and stops the platform in the event of an overload, no matter what height the platform is at. 7/ The lifting platform cannot be lowered or lowered with excessive force applied to each part of the lowering device, and therefore, there is no risk of damage to any part of the lowering device, and the work can be performed safely.

[Brief explanation of drawings]

Fig. 1 is a side view showing one embodiment of the elevating device of the present invention, Fig. 2 is a hydraulic circuit diagram of the safety mechanism of this elevating device, and Fig. 3 is an electric circuit for controlling the hydraulic circuit. It is a circuit diagram. FIG. 4 is a graph showing the relationship between the height of the 4 o'clock position and the oil pressure of the hydraulic cylinder. Explanation of symbols 3...4 Lowering mechanism 5...Soundproof stand 7a, 7b...Arm 8...Link mechanism 30... ......Hydraulic cylinder diagram 3

Claims (1)

[Claims] 1. A plurality of link mechanisms in which a pair of arms are rotatably connected at the center are arranged vertically, and adjacent link mechanisms are rotatably connected at the end of each arm to extend and retract in a pantograph style. A telescopic hydraulic cylinder that expands and contracts in the vertical direction in stages is installed between one arm and the other arm, and the hydraulic cylinder expands and contracts the lifting mechanism. In an elevating device that moves up and down an elevating platform attached to the top, a detection device is provided to detect the fluid pressure of the telescopic fluid pressure cylinder at each expansion/contraction stage, and the fluid pressure is detected at each expansion/contraction stage. An elevating device characterized by being provided with a control device that stops an elevating platform when a set value provided for each stage is exceeded.