JP2020075769A - Control means of work device - Google Patents

Abstract

To provide control means of a work device capable of stopping movement of a work floor to prevent interference between the work floor and some obstacle, as well as, of evacuating the working floor simply and rapidly from the stop position.SOLUTION: A control device II of a high lift work vehicle comprises: a main control part 11A for controlling movement of a work floor via a predetermined operation of an operation part 12, on condition that b-contacts L1b-L4b of an obstacle detection sensor installed on the work floor are operated to close when the work floor reaches a position causing interference with some obstacle, and that a make-contact Fa is closed via an operation of a main switch; and a safety control part 11B for prohibiting the main control part 11A from performing the above-mentioned control of the work floor even when the main switch is operated if at least one of the b-contacts L1b-L4b is opened by an operation of the obstacle detection sensor, and meanwhile, for allowing the main control part 11A to perform the above-mentioned controlling of the movement of a work floor on condition that the make-contact is closed by operations of the main switch operation and the emergency switch.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control means for a work apparatus, and is particularly useful when applied to an aerial work vehicle having a function of preventing interference between a work floor such as a basket and an obstacle.

  An aerial work vehicle is provided with a work floor (a place such as a basket on which an operator rides) that can be elevated to a high place, and enables a worker to perform a predetermined work at a high place. In this type of aerial work vehicle, the work floor is configured to move within a predetermined movement range.

  However, even if the work floor is moving within a predetermined movement range, if an obstacle exists in the movement range, interference between the obstacle and the work floor occurs. Therefore, various safety measures have been proposed to prevent such interference (for example, refer to Patent Document 1).

  However, from the viewpoint that the safety means according to the related art including Patent Document 1 has a complicated obstacle detection structure, the presence of the obstacle is easily and accurately detected and the movement of the work floor is appropriately stopped. It did not have a sufficient function. Furthermore, in the prior art, after stopping the work floor, the work floor cannot be quickly evacuated from the stop position. For this reason, there is a problem that it is not possible to smoothly shift to the next work avoiding the obstacle.

JP, 2016-55983, A

  In view of the above-mentioned conventional technology, the present invention is a work device capable of stopping the movement of the work floor so as to prevent interference between the work floor and an obstacle, and at the same time, easily and quickly retracting the work floor from the stop position. It is an object of the present invention to provide a control means of.

The first aspect of the present invention for achieving the above object is
A base, an elevating mechanism mounted on the base, a work floor for moving by the elevating mechanism and allowing an operator to board and perform a predetermined work, and a work floor arranged on the work floor for the worker. Control means for a working device having an operation section for operating the operation of the elevating mechanism by operation, and arranged on the work floor so as to operate when the work floor reaches a position where it interferes with an obstacle. An obstacle detection sensor,
A main control unit that controls the movement of the work floor by a predetermined operation of the operation unit on the condition of the operation of the main switch;
When the obstacle detection sensor operates by detecting that it has reached the position, the movement of the work floor by the operation of the operation unit is prohibited even when the main switch is operating, and the operation of the main switch is performed. And a safety control unit that allows the movement of the work floor by the operation of the operation unit on the condition of the operation of the emergency operation switch.

The second aspect of the present invention is
In the control means of the working apparatus according to the first aspect,
The safety control unit includes a make contact of the main switch, an a contact of a relay, a coil of the relay, a b contact of the obstacle detection sensor connected in series with the coil, and a b contact of the coil and the obstacle detection sensor. Between the contact and a make contact of the emergency operation switch connected in parallel with the b contact of the obstacle detection sensor,
During normal operation when the obstacle detection sensor is not operating, the coil is excited via the b contact of the obstacle detection sensor, and the a contact of the relay is closed, so that the operation of the main switch is performed. While enabling the movement of the work floor via the main control unit by a predetermined operation of the operation unit,
When the obstacle detection sensor operates abnormally, the b contact of the obstacle detection sensor is opened, the coil is deenergized, and the a contact of the coil is opened, so that the main switch operates to make the make. Even if the contact is closed, the control of the work floor by the main control unit is prohibited, and the make contact is closed by operating the emergency operation switch to excite the coil, and the a contact of the coil is closed. It is characterized in that movement of the work floor can be controlled by the main control section by a predetermined operation of the operation section on condition that the main switch is operated in a closed state.

A third aspect of the present invention is
In the control means of the working apparatus according to the first aspect,
The safety control unit includes a make contact of the main switch, a break contact of the main switch that is connected in parallel with the make contact and operates in synchronization with the make contact, and a make contact and a break contact of the main switch, respectively. An a contact of the relay connected to the relay, a b contact of the relay connected between one terminal of the break contact of the main switch and one terminal of the a contact of the relay, a coil of the relay, and the coil. A make contact of the emergency operation switch connected in parallel to the b contact of the obstacle detection sensor and the coil, which are connected in series,
During normal operation when the obstacle detection sensor is not operating, the coil is excited via the b contact of the obstacle detection sensor, and the a contact of the coil is closed to condition the operation of the main switch. While enabling the movement of the work floor via the main control unit by a predetermined operation of the operation unit,
When the obstacle detection sensor operates abnormally, the b contact of the obstacle detection sensor is opened, the coil is deenergized to open the a contact of the coil, and the b contact of the coil is closed. As a result, even if the main switch operates and the make contact is closed, the main control unit prohibits the control of the work floor, and the emergency contact switch is operated to close the make contact. To excite the coil and operate the main switch with the a-contact closed to allow the movement of the work floor to be controlled by the main control unit by a predetermined operation of the operation unit. Is characterized in that

A fourth aspect of the present invention is
In the control means of the working device according to any one of the first to third aspects,
The obstacle detection sensor is composed of a limit switch that operates when the obstacle is touched.

A fifth aspect of the present invention is
In the control means of the working device according to any one of the first to fourth aspects,
The main switch is a foot switch in which the make contact is closed by depressing a pedal with a foot.

A sixth aspect of the present invention is
In the control means of the working device according to any one of the first to fifth aspects,
The emergency operation switch is configured such that the make contact is closed while the operation portion is being operated, and the make contact is opened by releasing the operation. To do.

A seventh aspect of the present invention is
In the control means of the working device according to any one of the first to sixth aspects,
The elevating mechanism has a boom capable of undulating, extending and contracting, and turning, and the work floor is composed of a basket attached to the tip of the boom.

  According to the present invention, when the work floor reaches a position where it interferes with an obstacle as the work floor moves, the obstacle detection sensor detects this state and prohibits the movement of the work floor by the main operation unit. Therefore, the collision between the work floor and the obstacle can be prevented in advance. On the other hand, when the work floor is moved from the prohibition state to retract from the interference position, the prohibition state is released by operating the emergency operation switch, so by operating the main switch, The main control unit can move and control the work floor.

It is a schematic diagram which shows the whole aerial work vehicle to which the control system which concerns on embodiment of this invention is applied. It is a perspective view which extracts and expands the basket part of the aerial work vehicle shown in FIG. 1, and shows in detail. It is a block diagram which shows the control system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  This embodiment is an example of a control system for an aerial work vehicle as shown in FIG. However, the target to which the control method of the present invention is applied is not limited to an aerial work vehicle. The device is not limited to the vehicle as long as it has a work floor for a worker to board and perform a predetermined work, and is a device that moves up and down the work floor. Therefore, any working device having a base and an elevating mechanism having a work floor on the base can be widely applied to other than vehicles. That is, although the present embodiment is a vehicle in which the base can be self-propelled, it is not always necessary to configure the base so that it can be self-propelled.

  An aerial work vehicle I shown in FIG. 1 has a basket 2 which is a work floor attached to the tip of a boom 1. A worker 4 rides on the basket 2, while the boom 2 moves the basket 2. As a result, the worker 4 is allowed to perform a predetermined work at a high place within a work range (A + B) including a low travel range A and a travel stop range B in the figure. Here, the boom 1 includes a bending / extending boom 1A and a telescopic boom 1B. The bending / extending boom 1A has a base end portion attached to the swivel base 5 to perform a hoisting motion. A basket 2 is attached to the end of the telescopic boom 1B, and the position of the basket 2 is moved by expanding and contracting in the axial direction from the end of the bending / extending boom 1A. In addition, the swivel base 5 is arranged on the vehicle body 6 which is self-propelled via a crawler, and is formed so as to be swivelable in a horizontal plane.

  When performing a predetermined work at a height using such an aerial work vehicle, if there is an obstacle even within the predetermined work range (A + B), the obstacle is detected and the basket 2 is moved. The movement needs to be stopped. This is to prevent the basket 2 from colliding with an obstacle.

  Therefore, as shown in FIG. 2, the basket 2 of the aerial work vehicle I to which the present embodiment is applied is provided with limit switches L1, L2, L3, L4 which are obstacle detection sensors for detecting obstacles. is there. More specifically, the limit switches L1 to L4 are provided at the tips of the poles 3A, 3B, 3C and 3D that extend upward and are fixed to the four corners of the basket 2. Each of the limit switches L1 to L4 has actuators L1a, L2a, L3a and L4a extending upward and formed of a flexible member. This is because the actuators L1a to L4a bend when contacting an obstacle to absorb the impact at the time of contact.

  Thus, when the basket 2 moves with the possibility that the basket 2 interferes with an obstacle, one of the actuators L1a to L4a comes into contact with the obstacle and bends, so that the corresponding limit switch L1 to L4a. L4 operates to open its b-contact (which will be described later in detail with the control device). When such an abnormal state is detected, the normal movement / control of the basket 2 using the operation unit 12 and the foot switch F which is the main switch is prohibited. The prohibition state is released by operating the emergency operation switch SW and the foot switch F at the same time. The details of the control during this time will be described later with reference to FIG.

  FIG. 3 is a block diagram showing a control device for an aerial work vehicle according to this embodiment. As shown in the figure, the control device II ensures the safety of work of the aerial work vehicle I and a main control unit 11A formed by an ECU (electronic control unit) that controls the entire aerial work vehicle I. And a safety control unit 11B for. When the limit switches L1 to L4 (see FIG. 2; hereinafter the same) which are obstacle detection sensors detect obstacles and operate, the safety control unit 11B operates as a main switch foot switch F (see FIG. 2 below. , The same) are operating, the movement of the basket 2 (see FIGS. 1 and 2; the same applies below) by operating the operating portion 12 is prohibited, and the operation of the foot switch F and the emergency switch SW (see FIG. 2). The same applies hereinafter), and the movement of the basket 2 by the operation of the operation unit 12 is permitted.

  The main controller 11A operates the hydraulic cylinder 14 via an electromagnetic valve 13 that is controlled to be opened and closed by operating the operation unit 12 having a joystick. By the operation of the hydraulic cylinders 14, the booms 1 (see FIG. 1; the same applies hereinafter) of the work platform I are expanded and contracted by the hydraulic cylinders 14 to control the basket 2 to move to a predetermined position.

  In the safety control unit 11B, C is a coil of the relay R, Ra is an a contact of the relay R, Rb is a b contact of the relay R, Fa is a make contact of the foot switch F, Fb is a break contact of the foot switch F, and L1b and L2b. , L3b, L4b are b contacts of the limit switches L1 to L4.

  As a result, when the foot switch F operates, the make contact Fa is closed and the break contact Fb is opened. That is, between the make contact Fa and the break contact Fb of the foot switch F, the other is opened when one is closed and the other is closed when one is opened, so that a so-called interlock is realized. The a contact Ra is between the COM (+ 12v) terminal of the main control unit 11A and the make contact Fa, and the b contact Rb is between the main control unit 11A side of the a contact Ra and the main control unit 11A side of the break contact Fb. It is connected. One of the coils C of the relay R having the a-contact and the b-contact is connected to its COM terminal on the main control section 11A side of the a-contact, and the other is connected to the b-contact L4b of the limit switch L4. Here, the b contacts L1b, L2b, L3b, L4b of the limit switches L1 to L4 are connected in series with each other. Further, the emergency operation switch SW has its make contact SWa connected in parallel to the b contacts L4b, L3b, L2b, L1b between the coil C and the b contact L4b. The emergency operation switch SW in the present embodiment can be preferably formed by a push button switch, but in any case, a switch in which the make contact SWa is closed only while the operation such as pushing the push button is continued is used. ..

The control by the control device II configured as described above is executed in the following manner.
1) Normal time (when the basket 2 is moving without interfering with obstacles)
Since none of the limit switches L1 to L4 is operating, the b contacts L1b to L4b are all closed. As a result, the coil C of the relay R is excited to close the a-contact Ra and open the b-contact Rb. When the foot switch F is depressed in this state, the make contact Fa is closed and at the same time the break contact Fb is opened.

  In this state, in the present embodiment, the ON / OFF of the solenoid valve 13 is controlled via the main control section 11A by performing a predetermined operation of the operation section 12 formed by a joystick, and the hydraulic cylinder 14 is appropriately driven to drive the boom 1 To move the basket 2 to a predetermined position.

2) When abnormality is detected (when limit switches L1 to L4 are operating)
Even if the basket 2 is within a predetermined working range (A + B) (see FIG. 1; the same applies hereinafter), any one of the limit switches L1 to L4 comes into contact with an obstacle to cause one of the b contacts L1b to L4b. Is released, the coil C of the relay R is deenergized. As a result, the a contact Ra is opened and the b contact Rb is closed.

  In such a state, the solenoid valve 13 cannot be operated even if the foot switch F is depressed and the operation portion 12 is operated. This is because the coil C of the relay R is deenergized and the a-contact Ra is opened. Thus, movement of the basket 2 via the boom 1 is prohibited.

3) When the abnormal condition is released (when the basket 2 is retracted from the emergency stop position)
When the movement of the basket 2 is prohibited by the operation of the limit switches LS1 to LS4, the emergency switch SW is activated (in the case of a push button switch, the switch button is pressed). As a result, by exciting the coil C, the a contact Ra is closed and the b contact is opened. This is the same mode as the normal time. Therefore, if the foot switch F is depressed as in the normal state, the make contact Fa is closed, and at the same time, the break contact Fb is opened. As a result, the solenoid valve 13 can be controlled by operating the operating portion 12 and the hydraulic cylinder 14 can be driven to move the basket 2 as in the normal state. As a result, the operating states of the limit switches L1 to L4 are released. Here, since the emergency switch SW is operated and the make contact SWa is closed while being pressed, the excited state of the coil C is also continued. Therefore, while the emergency switch SW is being pressed until the contact between the limit switches L1 to L4 and the obstacle is released, the operating portion 12 is simultaneously operated to move the basket 2 to a position where there is no buffer against the obstacle.

  Although FIG. 1 shows a boom-type aerial work vehicle, this may of course be another type, for example, a vertically elevating aerial work vehicle. Here, the vertical lifting type has a structure in which a platform, which is a work floor, vertically moves up and down. The aerial work vehicle which is the subject of the present invention is 1) having a work floor (a place where the work vehicle gets on during work) that can rise to a height of 2 m or more, and is composed of a lifting device, a traveling device, and the like. If there are three conditions, 2) using power other than human power to raise and lower the work floor, 3) being able to self-propelled to an unspecified place There is no limit.

  Further, in the above embodiment, the limit switches L1 to L4 are used to detect the obstacle above the bucket 2, but the present invention is not limited to this. For example, it can be configured to be used for detecting an obstacle existing in the horizontal direction. In this case, for example, the limit switches L1 to L4 may be projected from the basket 2 in the horizontal direction. The limit switches L1 to L4 as the obstacle detection sensor are not limited to this. For example, a proximity sensor can be substituted.

  Further, the main switch is not limited to the foot switch F. A switch that operates a master key type key may be used.

I Aerial work vehicle
II Control device A + B Working range F Foot switch 1 Boom 2 Basket 4 Worker 11A Main control unit 11B Safety control unit 12 Operation unit L1 to L4 Limit switch R Relay C Coil SW Emergency operation switch

Claims (7)

A base, an elevating mechanism mounted on the base, a work floor for moving by the elevating mechanism and allowing an operator to board and perform a predetermined work, and a work floor arranged on the work floor for the worker. Control means for a working device having an operation section for operating the operation of the elevating mechanism by operation, and arranged on the work floor so as to operate when the work floor reaches a position where it interferes with an obstacle. An obstacle detection sensor,
A main control unit that controls the movement of the work floor by a predetermined operation of the operation unit on the condition of the operation of the main switch;
When the obstacle detection sensor operates by detecting that it has reached the position, the movement of the work floor by the operation of the operation unit is prohibited even when the main switch is operating, and the operation of the main switch is performed. And a safety control unit for permitting movement of the work floor by operation of the operation unit on condition of the operation of the emergency operation switch. In the control means of the working device according to claim 1,
The safety control unit includes a make contact of the main switch, an a contact of a relay, a coil of the relay, a b contact of the obstacle detection sensor connected in series with the coil, and a b contact of the coil and the obstacle detection sensor. Between the contact and a make contact of the emergency operation switch connected in parallel with the b contact of the obstacle detection sensor,
During normal operation when the obstacle detection sensor is not operating, the coil is excited via the b contact of the obstacle detection sensor, and the a contact of the relay is closed, so that the operation of the main switch is performed. While enabling the movement of the work floor via the main control unit by a predetermined operation of the operation unit,
When the obstacle detection sensor operates abnormally, the b contact of the obstacle detection sensor is opened, the coil is deenergized, and the a contact of the coil is opened, so that the main switch operates to make the make. Even if the contact is closed, the control of the work floor by the main control unit is prohibited, and the make contact is closed by operating the emergency operation switch to excite the coil, and the a contact of the coil is closed. In the working device, the movement of the work floor can be controlled by the main control unit by a predetermined operation of the operation unit on condition that the main switch is operated in a closed state. Control means. In the control means of the working device according to claim 1,
The safety control unit includes a make contact of the main switch, a break contact of the main switch that is connected in parallel with the make contact and operates in synchronization with the make contact, and a make contact and a break contact of the main switch, respectively. An a contact of the relay connected to the relay, a b contact of the relay connected between one terminal of the break contact of the main switch and one terminal of the a contact of the relay, a coil of the relay, and the coil. A make contact of the emergency operation switch connected in parallel to the b contact of the obstacle detection sensor and the coil, which are connected in series,
During normal operation when the obstacle detection sensor is not operating, the coil is excited via the b contact of the obstacle detection sensor, and the a contact of the coil is closed to condition the operation of the main switch. While enabling the movement of the work floor via the main control unit by a predetermined operation of the operation unit,
When the obstacle detection sensor operates abnormally, the b contact of the obstacle detection sensor is opened, the coil is deenergized to open the a contact of the coil, and the b contact of the coil is closed. As a result, even if the main switch operates and the make contact is closed, the main control unit prohibits the control of the work floor, and the emergency contact switch is operated to close the make contact. To excite the coil and operate the main switch with the a-contact closed to allow the movement of the work floor to be controlled by the main control unit by a predetermined operation of the operation unit. The control means of the working device, wherein In the control means of the working device according to any one of claims 1 to 3,
The control means for a working device, wherein the obstacle detection sensor is composed of a limit switch that operates when contacting the obstacle. In the control means of the working device according to any one of claims 1 to 4,
The control means of the working device, wherein the main switch is a foot switch in which the make contact is closed by depressing a pedal with a foot. In the control means of the working device according to any one of claims 1 to 5,
The emergency operation switch is configured such that the make contact is closed while the operation portion is being operated, and the make contact is opened by releasing the operation. Means for controlling the working device. In the control means of the working device according to any one of claims 1 to 6,
The control means for a working device, wherein the lifting mechanism has a boom capable of undulation, extension and contraction, and swiveling, and the work floor is composed of a basket attached to a tip of the boom.

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