JPH0774080B2 - Lift car - Google Patents

Description

The present invention relates to a bucket lift type lift truck. That is, for example, when moving, a lift truck that loads luggage into a bucket and transports it between the ground and a target at a high place, a lift truck for high-altitude construction work that similarly transports materials at a construction site, fire fighting in case of fire It also relates to lift trucks for the work of digesting a high place, which also carries technicians, equipment, and people who evacuate.

"Prior Art" In a conventional lift truck, when a bogie that moves up or down reaches a boom tip or a base end, position detection of a bogie such as a switch mounted on the boom tip or the base end is detected. By operating the means and controlling the electromagnetic proportional control valve through the relay circuit, the drive motor is automatically stopped to control the lifting and lowering of the carriage.

"Problems to be Solved by the Invention" By the way, the following problems have been pointed out in such a conventional example. In other words, since the moving speed of the bogie that moves up and down due to the influence of acceleration, etc. due to the change in the load amount is not constant, it is not possible for the operator to smoothly stop the bogie at a predetermined position such as the tip of the boom or the rearmost end. There is a problem in that personal skill is indispensable, and in the case of sudden stop, a load collapse accident of luggage loaded on the trolley occurs.

The present invention has been made in view of the above circumstances in order to solve the problems of the above-described conventional example, and the lifting work of the lift truck by the lift truck can be easily performed without depending on the personal skill of the operator. The purpose is to provide a lift vehicle that can be smoothly controlled.

"Means for Solving Problems" The technical means of the present invention for achieving this object are as follows.

This lift car is capable of undulating, expanding and contracting on the vehicle body,
And a rotatably mounted boom, a trolley that is moved up and down along the boom, and a bucket that is pivotally supported on the trolley and that holds loads, people, etc. horizontally and is held horizontally, First, the following four detection means are provided.

The first detection means is for detecting the stop position of the truck that is arranged at the tip of the boom and moves up.

The second detection means is arranged on the boom at an interval preset as a deceleration section by the first detection means, and detects the deceleration start position of the ascending carriage.

The third detecting means is arranged on the boom at a predetermined distance from the boom base end portion and detects the deceleration start position of the descending carriage.

The fourth detecting means is for detecting the stop position of the carriage that is arranged at the base end of the boom and descends.

Further, it further comprises the following hydraulic pump, hydraulic motor, winch device, electromagnetic proportional flow control valve, and the like. That is,
A hydraulic pump driven by the engine of the vehicle body;
A hydraulic motor that is connected to the hydraulic pump via hydraulic piping and is capable of rotating in the forward and reverse directions, and is stretched between the bogie equipped with wheels so as to travel between the boom front end and the boom base end. And a winch device for raising and lowering the wire, which is connected to the hydraulic motor, and is installed in the hydraulic pipe between the hydraulic pump and the hydraulic motor.
And an electromagnetic proportional flow control valve for performing control such as deceleration and stop based on the detection results of the first, second, third and fourth detection means.

"Working" The present invention is constituted by such means, and therefore operates as follows.

The first and second detection means detect a stop position and a deceleration start position of the ascending carriage. Further, the third and fourth detection means detect the deceleration start position and the stop position of the descending carriage. Based on the detection results of the first, second, third, and fourth detection means, the hydraulic motor and the winch device are controlled by the electromagnetic proportional flow rate control valve that is the drive motor control means.

That is, first, when the trolley moves up to reach the position of the second detecting means, the electromagnetic proportional flow rate control valve is controlled based on the detection result of the second detecting means that detects this, and the electromagnetic proportional flow rate control valve The opening degree becomes smaller, the hydraulic flow rate until then is throttled, the rotation of the hydraulic motor and the winch device is decelerated, and the deceleration of the truck is started. When the bogie during deceleration and ascent further rises to reach the boom tip, the electromagnetic proportional flow control valve is controlled based on the detection result of the first detection means that detects this, and the electromagnetic proportional flow control valve is closed. , The hydraulic motor and winch device stop, and the dolly stops at a predetermined position.

On the other hand, when the carriage descends and reaches the position of the third detecting means, the electromagnetic proportional flow control valve is controlled based on the detection result of the third detecting means that detects this, and the electromagnetic proportional flow control valve is opened. Degree becomes smaller and the hydraulic flow rate up to that point is throttled,
The rotation of the hydraulic motor and the winch device is decelerated, and the deceleration of the carriage is started. When the carriage being decelerated and descending further descends to reach the position of the fourth detecting means at the boom base end,
The electromagnetic proportional flow rate control valve is controlled based on the detection result of the fourth detecting means that detects this, the electromagnetic proportional flow rate control valve is closed, the hydraulic motor and the winch device are stopped, and the carriage is stopped at a predetermined position. .

In this way, the lift truck starts decelerating at the preset deceleration start position and smoothly stops at the predetermined stop position. Therefore, firstly, the lifting and lowering work of the truck in the lift truck can be performed easily without relying on the personal skill of the operator, and safely without a runaway accident. Secondly, the electromagnetic proportional flow control valve controlled by each detecting means is interposed between the hydraulic pump driven by the vehicle engine and the hydraulic motor of the lifting winch device. It is realized by the control mechanism. In this way, the above-mentioned first point is realized by the control mechanism that specifically adjusts the power on the downstream side and the operating side while using the vehicle engine as the drive source as it is, so that the overall cost is low. In addition to "Example", there are few malfunctions, and the bogies are decelerated, stopped, and lifted and lowered smoothly.

The present invention will be described in detail below based on the embodiments shown in the drawings.

First, a lift car will be described.

FIG. 3 shows a general lift truck 1, and FIG. 4 shows
It is the usage explanatory drawing.

The lift vehicle 1 includes not only the self-propelled type illustrated, but also a towed type that does not have any action, both of which can turn on the chassis 6 and can be undulated.
In addition, a boom 2 that is extendable and retractable is provided. A trolley 3 is moved up and down along the boom 2, and a bucket 14 that stores, for example, luggage C is a veranda V of a middle-to-high-rise building B that is a work place higher than the trolley 3. Etc.

The boom 2 will be described in detail. A turntable 7 is rotatably mounted on the chassis 6, and the boom 2 is pivotally supported on the turntable 7 by a cylinder 8 and a pin 9 so that the boom 2 can be raised and lowered. The boom 2 is of a multi-stage type that can be expanded and contracted, and is extended and stored from the second stage onward by a drive mechanism (not shown) using a cylinder, a wire, and the like. Boom 2 is a nested multi-stage boom,
There are so-called ladder-like multi-stage booms such as ladders, square cross-sections, flat cross-sections, straight type, refraction type, and various other types and shapes.

As will be described later in detail, the uppermost boom of the multistage boom 2 is provided with the first and second detecting means, and the lowermost boom is provided with the third and fourth detecting means. To be done.

Explaining the carriage 3 in detail, the carriage 3 is moved up and down along the boom 2. That is, the trolley 3 is provided with wheels 10 and is provided with a wire 41 stretched in the front and rear thereof by a winch device 4 for lifting and lowering connected to a hydraulic motor 5 capable of rotating in the forward and reverse directions.
By unwinding and winding up, the robot 2 travels on the boom 2 between its distal end portion 21 and its proximal end portion 24.

In the illustrated example, this dolly 3 has a pedestal 12 such as a loading platform and a work platform which are pivotally supported by pins 11 on the dolly 3, and the pedestal 12 is horizontally placed between the dolly 3 and the pedestal 12. Control and trolley 3
An attitude control mechanism such as a tilt mechanism 13 supported above is provided. Then, a box-shaped bucket 14 accommodating a load such as luggage C is mounted on such a pedestal 12 and transported by the trolley 3.

In the figure, T is a truck for transporting luggage C and the like, and M is a worker.

The lift car is configured in this way.

Next, a control mechanism for decelerating and stopping the truck 3 that moves up and down will be described.

FIG. 1 is a block diagram of a truck drive control of a lift truck showing an embodiment of the present invention.

The tip 21 of the uppermost boom of the multi-stage boom 2 has a first
The switch S1 which is the detecting means of the second switch is the switch S2 which is the second detecting means at the interval 22 corresponding to the deceleration section at the time of rising.
Are respectively arranged. Also, the base end of the bottom boom
A switch S4 as a fourth detecting means is provided at 24, and a switch S3 as a third detecting means is provided at 23 with an interval corresponding to the deceleration section at the time of descending. Each of these switches S1 to S4 is connected to the control power source via the control valve controller HC.

On the other hand, the winch device 4 for raising and lowering the carriage 3 is connected to a hydraulic motor 5 capable of rotating in the forward and reverse directions. The hydraulic motor 5 is connected to a hydraulic pump HP via a hydraulic pipe 52 via an electromagnetic proportional flow rate control valve HV. Further, the electromagnetic proportional flow rate control valve HV is connected to the control power source through the control panel controller HC via the control panel CB.

FIG. 2 is a detailed view of the control mechanism of FIG.

The hydraulic power source device HU includes a hydraulic pump HP driven by the engine E of the vehicle body 1, a hydraulic oil tank HT and a relief valve.
Composed of HL.

The control valve controller HC includes control relays CR1 to CR4 corresponding to the switches S1 to S4, which are position detecting means of the carriage 3,
Control relays CR5 and CR6, which correspond to the switch S5 for instructing the up and down movement of the trolley 3, are provided, and the electromagnetic proportional flow rate control valve HV is provided through each contact of these control relays.
And the control current generator AV are connected. This control current generator AV is a potentiometer VR for setting the moving speed of the trolley 3 via each contact of the control relay, and fixed resistors R1, R2.
Connected to.

The above is the description of the configuration. Next, the operation and the like will be described.

At the work site, the lift vehicle 1 first turns, erects, and extends the boom 2 on the undercarriage 6, and the tip end portion 21 thereof is arranged to face the veranda wall of the veranda V of the middle-high-rise building B, which is the work target.

Next, when the operator sets the lever switch S5 on the operation panel CB to the up side, the control current is input from the control current generator AV to the electromagnetic proportional flow rate control valve HV via the control relays CR5 and CR1, and the The proportional flow rate control valve HV opens to the upward side, the hydraulic motor 5 rotates forward, the winch 4 winds the wire 41, and the carriage 3 is raised.

When the truck 3 further rises to reach the 22 point on the boom 2, the switch S2 is brought into contact with the weight of the truck 3, the corresponding control relay CR2 is excited, and its contact CR2s is switched to the deceleration mode. As a result, the control current generator AV
The control voltage to be input to is reduced by the fixed resistance R2, and the output current of the control current generator AV is reduced, so that the opening degree of the valve on the rising side of the electromagnetic proportional flow control valve HV is reduced. As a result, the amount of hydraulic oil flowing into the hydraulic motor 5 is reduced, the rotational speed of the hydraulic motor 5 is reduced, and the carriage 3 decelerates and rises.

When the carriage 3 further decelerates and rises to reach the tip 21 of the uppermost boom, the switch S1 comes into contact with the weight of the carriage 3,
Relay CR1 is excited and its contact CR1s is connected. As a result, the control current to the solenoid proportional flow control valve HV is cut off,
The dolly 3 stops at a predetermined boom tip.

On the other hand, in the case of descending, the operator sets the lever switch S5 on the operation panel CB to the descending side, so that the electromagnetic proportional flow rate control valve HV released from the control power supply again has CR6s and CR4s.
A control current from the control current generator AV is applied through the contact of the winch 4, the winch 4 rotates in the reverse direction, and the carriage 3 starts to descend. When the trolley 3 descends and reaches 23 on the lowest boom, the switch S3 comes into contact, and as a result, the control relay CR3 is excited, and its contact CR3s is switched to the deceleration mode.
The cart 3 is decelerated and descends. Then, when the trolley 3 reaches the base end portion 24 of the lowermost boom, the switch S4 detects this, and as a result, the control relay CR4 is excited and its contact CR4s is closed. As a result, the electromagnetic proportional flow control valve HV is closed and the carriage 3
Stops smoothly at the base end of the boom.

The above is the description of the operation and the like.

As described above, according to the present embodiment, by selecting the resistance value of the potentiometer VR by operating the operation lever switch S5, it is possible to arbitrarily set the optimum speed for each of the ascent and the descent and to move the cart at any position. It is possible not only to stop. Further, in this embodiment, since the control current is disconnected from the power source through the detecting means, it is effective to prevent the runaway of the trolley due to an erroneous operation during stoppage.

In the present embodiment, the limit switch is used as the position detecting means of the trolley 3, but it is also possible to use an optical sensor or the like as the detecting means.

"Effects of the Invention" As described above, in the lift vehicle according to the present invention, the position of the lift truck during the ascent and descent is detected by the two pairs of detection means and automatically controlled to detect the position of the operator. It is possible to surely and easily realize the operation of the lift truck without depending on the technical skill, and also to secure the safety of the work. That is, the ascending / descending state of the bogie is double checked for deceleration and stop, accidents due to runaway of the bogie are reliably prevented, and it is possible to smoothly stop the vehicle by decelerating it in advance. It is possible to effectively prevent the collapse of luggage.

Moreover, since these are realized by the control mechanism that specifically adjusts the power of the vehicle engine on the downstream side and the operating side while using the vehicle engine as a drive source, the overall cost is low, there are few failures, and it is smooth and smooth. The bogie is surely decelerated, stopped and lifted.

In this way, the problems existing in the conventional example of this type of lift truck are swept away at once, and the effect exerted by the lift truck is remarkable and great.

[Brief description of drawings]

FIG. 1 is a block diagram of a control mechanism for a lift truck of a lift truck showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the control mechanism of FIG. 1, and FIGS. 3 is a front view and FIG. 4 is an explanatory view showing an example of its use. 1 …… Lift truck 2 …… Boom 21 …… Top end of the uppermost boom 22 …… Starting point for deceleration of the uppermost boom 23 …… Starting point for deceleration of the lowermost boom 24 …… Base end of the lowermost boom 3 …… Truck 4 …… Winch device 41 …… Wire 5 …… Hydraulic motor 52 …… Hydraulic piping 6 …… Car chassis 10 …… Wheel 14 …… Bucket HV …… Electromagnetic proportional flow control valve HC …… Control valve controller AV …… Control current Generator HP ... hydraulic pump S1 ... switch (first detection means) S2 ... switch (second detection means) S3 ... switch (third detection means) S4 ... switch (fourth detection means) ) S5 …… Operating lever switch CR1 ～ 6 …… Control relay CR1s ～ 4s …… Control relay contacts R1, R2 …… Fixed resistor VR1 …… Potentiometer CB …… Control panel

Claims (1)

[Claims] 1. A boom mounted on a vehicle body so as to be capable of undulating, expanding and contracting, and swinging, a dolly that is moved up and down along the boom, and luggage, people, etc. that are pivotally supported on the dolly. In a lift vehicle having a bucket that is held horizontally, the first detection means that detects the stop position of the truck that is disposed at the tip of the boom and that moves upward, and the first detection means Second detection means arranged at a set distance to detect the deceleration start position of the ascending carriage, and deceleration start position of the carriage arranged at a preset distance from the boom base end and descending. And a fourth detecting means for detecting the stop position of the descending carriage, which is disposed at the base end of the boom, and is driven by the engine of the vehicle body. Hydraulic pump,
A hydraulic motor that is connected to the hydraulic pump via hydraulic piping and is capable of rotating in the forward and reverse directions, and is stretched between the bogie equipped with wheels so as to travel between the boom front end and the boom base end. And a winch device for feeding and winding the wire, which is connected to the hydraulic motor, and is connected to the hydraulic motor and the hydraulic pipe between the hydraulic pump and the hydraulic motor. A lift vehicle, comprising: an electromagnetic proportional flow rate control valve that performs control such as deceleration and stop based on the detection result of each of the fourth detection means.