JPH0344746Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial field of application" This invention relates to a conveyance device used in factories, warehouses, etc., and is particularly designed to perform running control such as acceleration, deceleration, and stopping of a moving object with a simple configuration. The present invention relates to a conveying device capable of

"Prior Art" For example, as a conveyance means in a product assembly conveyance line, etc., as shown in Fig. 3 A and B,
2. Description of the Related Art A conveying device using a single-sided linear induction motor (hereinafter abbreviated as LIM) as a drive source is known. In this figure, 1 is a pair of free roller conveyors provided along the conveyance path, 2 is movably supported by rollers 3, 3, . . . of the free roller conveyor 1, and a conveyed object 4 is loaded thereon. It is a palette. M ₁ , M ₂ . . . are arranged at predetermined intervals on the conveyance path and are responsible for generating a traveling magnetic field, and 7 is attached to the lower surface of the pallet 2, and the primary side of the LIM M ₁ , M ₂ . . . facing each other with a gap above and below
It is the secondary conductor of LIM. 8 is the primary side of an electromagnet for positioning and stopping provided at a station ST of the conveyance path (for example, a place where the conveyed objects 4 loaded on the pallet 2 are processed and the conveyed objects 4 are loaded and unloaded); A secondary iron core 9 is attached to the lower surface of the pallet 2 and faces the primary side 8 of the electromagnet with a gap above and below, and _S0 to _S3 are provided along the conveyance path to detect the position of the pallet 2. It is a position sensor.

In such a configuration, the primary side M ₁ of the LIM,
By adjusting the supply voltage to M ₂ ..., the strength of the thrust acting on the pallet 2 changes,
Furthermore, the direction of the thrust acting on the pallet 2 can be switched by exciting the primary sides M ₁ , M _{2 . .} . in positive or negative phase. Based on the detection signals of the position sensors S ₀ to _{S 3} , a drive control circuit (not shown) controls the excitation of the primary sides M ₁ , M ₂ . It can be moved with .

This will be explained with reference to FIG. 3C. first,
Pallet 2 stops above the primary side _M1 of the LIM,
While this is being detected by the position sensor _S0 , when the primary side _M1 of the LIM is excited in positive phase with a normal voltage, the pallet 2 is moved in the forward direction (Fig. 3A,
A thrust force in the direction shown by the arrow is applied to the pallet 2, thereby accelerating the pallet 2. When the pallet 2 passes the position sensor _S1 , the power supply to the primary side _M1 is cut off, and the pallet 2 coasts thereafter. Then pallet 2 is the station
When the position sensor S ₂ detects that it has reached just before ST, a backward thrust (braking force) is applied to the pallet 2 by energizing the primary side M ₂ with a normal voltage in reverse phase. , whereby the pallet 2 is decelerated. When the pallet 2 has been sufficiently decelerated, the primary side _M2 is now excited in positive phase with a low voltage to move the pallet 2 at a low speed, and then the pallet 2 is detected by the position sensor _S3. At the same time, the power supply to the primary side M ₂ is cut off, and at the same time, an excitation voltage is applied to the primary side 8 of the positioning electromagnet, and a voltage is applied between the primary side 8 and the secondary side iron core 9. The pallet 2 is positioned and stopped at the station ST by the magnetic attraction force.
The objects 4 loaded on the pallet 2 in this manner are transported to an arbitrary station ST.

The above example is a ground primary system in which the primary sides M ₁ , M _{2 .} . . of the LIM are provided on the conveyance path side.Next, the ground secondary system will be explained with reference to FIG. 4. In this figure, the pallet 2 is provided with wheels 12 and guide rollers 13, so that the pallet 2
is movably guided along the track 14. In addition, the secondary side conductor 7 of the LIM is attached to the track 14, and the primary side M of the LIM is attached to the lower surface of the pallet 2, and a 3-phase AC power source is connected to this primary side M from the ground via the power supply device 15. Supplied. This power supply device 15 includes three-phase power supply lines 16a, 16b, and 16c provided along the conveyance path, and three-phase power supply lines provided on the pallet 2 side and slidably in contact with the power supply lines 16a, 16b, and 16c, respectively. Minute collectors 18a, 18b,
18c etc. The operating principle of this terrestrial secondary system is similar to the previously mentioned terrestrial primary system.

"Problems to be Solved by the Invention" By the way, the above-mentioned conventional conveying device had the following problems.

For each station ST, the acceleration end position,
Three position sensors S ₁ to S ₃ (see Figure 3 B and C) must be installed to detect the deceleration start position and stop position, and as a result, as the number of stations ST increases, The configuration becomes complicated.

Based on the detection results of each position sensor S ₀ ~ S ₃ ,
A function to adjust the supply voltage to the primary side M or M ₁ , M ₂ ... of the LIM, and the primary side M or M ₁ ,
In order to configure a LIM drive control circuit that has the function of switching the excitation of M ₂ ... between positive phase and negative phase, a large number of semiconductor elements such as expensive thyristors and power transistors are required.
The entire conveying device becomes expensive.

Since the pallet 2 is accelerated indefinitely regardless of the weight of the loaded objects 4, if the weight of the objects 4 is large, a large impact force is applied to the objects 4 during deceleration. As a result, there is a risk that the load may collapse or a failure may occur if the transported object 4 is a precision part or the like.

This idea was made in view of the above-mentioned circumstances, and it is possible to perform traveling control such as acceleration, deceleration, and stopping of the trolley with a simple configuration, and it is possible to perform running control such as acceleration, deceleration, and stopping of the trolley, and to adjust the speed according to the weight of the objects loaded on the trolley. The object is to provide a conveying device that can convey at high speed.

"Means for Solving the Problem" This invention consists of a drive means for moving the cart along a conveyance path, a control line provided along the conveyance path, and a predetermined potential distribution set on the control line. a contactor provided on the trolley and slidably in contact with the control line; a speed detection means for outputting a speed detection signal according to the moving speed of the trolley; weight detection means for detecting the weight of the transported object; and means for adjusting and outputting the potential of the control line detected via the contactor according to the weight detected by the weight detection means. an adjusting means for outputting a signal with a smaller signal value as the detected weight is larger when the potential of the control line is constant; It is characterized by comprising a control means for turning on the driving means.

"Operation" The weight of the transported object loaded on the trolley is detected by the weight detection means, and the potential of the control line provided along the transport path, that is, the potential that changes depending on the position of the trolley, is detected by the contact. Further, the detected potential of the control line is adjusted by the adjustment means according to the weight of the object to be transported and output. Here, when the potential detected via the contact is constant, the heavier the object to be transported, the smaller the output signal value of the adjustment means. Then, when the output signal of the adjusting means is larger than the speed detection signal, the driving means is turned on by the control means. In this way, at each position on the transport path, the carriage is controlled to travel at a speed appropriate to the weight of the object to be transported, in accordance with the potential of the control line at that position.

"Embodiments" Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration when an embodiment of this invention is applied to a ground secondary type conveyance device using the LIM shown in FIG. 4 as a drive source.
Components corresponding to those in FIG. 4 are given the same reference numerals, and their explanations will be omitted.

In FIG. 1, 20 is a control line, 21 is a conducting wire made of a highly conductive material such as copper, and these are installed along the track 14.
The control wire 20 has a conductor portion 20 made of the same material as the conductor 21.
a and resistance wire portions 20b with low conductivity are connected alternately, and each station ST 1 is a deceleration area where the pallet 2 is decelerated and stopped, that is, each station ST ₁ ,
A resistance wire portion 20b is arranged in the region in front of ST _{2 .} . . , and a conductor wire portion 20a is arranged in the other region. In addition, the conductive wire portion 20a and the resistance wire portion 20b
It is a connection point for each station ST ₁ , ST ₂ ...
The connection portions C ₁ , C ₂ . . . corresponding to the voltage setting device 19 are respectively connected to the terminals T ₁ , T ₂ . has been done. Voltage setting device 19
has a function of setting a predetermined potential distribution between each station ST ₁ , ST ₂ . . . of the control line 20 with the conducting wire 21 as a reference. For example, by setting the voltage of terminal T ₁ with respect to the common terminal Tc higher than that of terminal T ₂ , a constant potential is set in the conductor portion 20a between station ST ₁ and station ST ₂ , and the voltage of the resistor A voltage characteristic is set in which the potential that changes depending on the position of the wire portion 20b, that is, the voltage between the resistance wire portion 20b and the conducting wire 21, decreases linearly as it approaches the station _ST2 .

On the other hand, the pallet 2 is provided with contacts 22 and 23, a tachometer generator 24, a relay 25, a LIM control circuit 30, a weight detector 32, and a voltage adjustment circuit 33. To explain these in detail, contact 2
2 and 23 are provided so as to be in slidable contact with the control line 20 and the conducting wire 21, and their mechanical configuration is similar to the aforementioned collectors 18a to 18c (see FIG. 4). The tachogenerator 24 outputs a DC voltage according to the rotation speed of the wheels 12, and the rotation of the wheels 12 is transmitted through a transmission mechanism such as a gear or a belt. The relay 25 is a differential coil type relay, and includes a U-shaped fixed core 26, coils _L1 and L2 wound around the fixed core 26 in opposite directions, and coils L1 and _L2 wound around the fixed core ₂₆ in opposite directions.
A movable core 27 that moves in the direction of arrow A or B when a different voltage is applied to _L2 , and a movable core 27 that moves in the direction of arrow A or B when a different voltage is applied to
The movable contact 28 attached to 7 and the movable iron core 2
It is composed of a movable contact 28 and a fixed contact 29 that comes into contact when the contact 7 moves in the direction of arrow A. One end of the coil _L1 is connected to the contactor 22 via a voltage adjustment circuit 33, which will be described later, and the other end is connected to the contactor 23.
It is connected to the. Further, both ends of the coil L ₂ are connected to the tachometer generator 24, and the coils L ₁ and L ₂
A common connection is made between each end. in this case,
If (voltage PV applied to coil L ₁ ) > (voltage SV applied to coil L ₂ ), movable iron core 2
7 moves in the direction of arrow A, and conduction is established between the movable contact 28 and the fixed contact 29. Further, the LIM drive circuit 30 operates according to the conduction state between the movable contact 28 and the fixed contact 29 of the relay 25.
It controls the operation of the primary side _M1 of the LIM, and when the contacts 28 and 29 are in a conductive state, the collector 18a
~18c and the primary side M of the LIM, thereby connecting the feeder lines 16a to 16c to the primary side M.
When three-phase commercial AC power is supplied through the collectors 18a to 18c and the contacts 28 and 29 are in a non-conducting state, the collectors 18a to 18c and the LIM
The supply of three-phase commercial AC power to the primary side M is cut off.

A weight detector 32 detects the weight of the objects loaded on the pallet 2, is composed of a load cell, etc., and supplies a detection signal corresponding to the weight to the voltage adjustment circuit 33. The voltage adjustment circuit 33 adjusts the voltage detected by the contacts 22 and 23, that is, the level of the voltage between the conductive wire 21 and the control wire 20, according to the detection signal supplied from the weight detector 32, and This is what is supplied to the coil _L1 .

Next, the operation of the conveying device having the above-described structure will be explained with reference to FIG. 2A, B, and C.

In this case, the voltage setting device 19 applies DC E [V] to the terminal T ₁ and 0 to the terminal T ₂ with reference to the common terminal Tc.
Set [V] and set palette 2 to station ST _1.
An example of traveling from to station ST ₂ will be explained.

First, between the station ST ₁ and the station ST ₂ of the control line 20, as shown by the dotted line in FIG.
A constant potential is set in _X1 , and a potential that changes depending on the position is set in the deceleration region _X2 where the resistance line portion 20b is provided. That is, the control line 20
The voltage between the conductor 21 and the conductor ₂₁ becomes _a constant E [V] in _the acceleration/constant speed region
A voltage characteristic that linearly decreases from [V] to 0 [V] is set.

Here, when the pallet 2 is stopped at the station _ST1 , the DC voltage SV output from the tachogenerator 24 and applied to the coil _L2 of the relay 2 is
is 0 [V]. Also, the contacts 22 and 23 are connected between the station ST ₁ part of the control line 20 and the conductor 21.
The voltage detected through is E [V], and the voltage PV adjusted by the voltage adjustment circuit 33 and applied to the coil L ₁ is E ₁ [V], therefore,
(Voltage PV applied to coil L ₁ )>(Voltage SV applied to coil L ₂ ), movable core 27 of relay 2 moves in the direction of arrow A, and the distance between movable contact 28 and fixed contact 29 increases. Conduct. This results in
The LIM control circuit 30 is connected to the collectors 18a to 18c.
The primary side M of the LIM is connected, and as shown in FIG.
As a result, pallet 2 starts moving.

After that, the pallet 2 travels at an accelerated speed, and as the moving speed of the pallet 2 increases, the output voltage SV of the tachogenerator 24 increases as shown by the curve in FIG.
rises. Further, the voltage between the control line 20 and the conductor 21 detected by the contacts 22 and 23 is E
[V] remains constant, and therefore the voltage PV applied to the coil _L1 via the voltage adjustment circuit 33
remains constant at E ₁ [V].

Next, when the pallet 2 moves to the position indicated by _P1 in Figure 2A, (voltage PV applied to coil _L1 ) < (voltage SV applied to coil _L2 ), and relay 2 becomes movable. The iron core 27 moves in the direction of arrow B shown in FIG. 1, and the contacts 28 and 29 are brought into a non-conducting state. As a result, the LIM control circuit 30 cuts off the connection between the current collectors 18a to 18c and the primary side M of the LIM, and the supply of drive voltage to the primary side M is cut off as shown in FIG. 2B. Thereafter, the pallet 2 travels by inertia, accelerates slightly, and then shifts to deceleration. As the moving speed of the pallet 2 decreases, the output voltage SV of the tachogenerator 24 decreases.

Next, when the pallet 2 moves to the position indicated by _P2 in Figure 2A, (voltage applied to coil _L1 ) > (voltage applied to coil _L2 ) again.
SV), and the power supply line 16a is connected to the primary side M.
A driving voltage is supplied from ~16c. Thereafter, the pallet 2 decelerates slightly and then shifts to accelerated travel.

In this way, in the acceleration/constant speed region _X1 where the conductor section 20a between the stations _ST1 and _ST2 is provided, three-phase AC power is intermittently supplied to the primary side M of the LIM, and the pallet 2 alternately repeats acceleration and deceleration, whereby the pallet 2 is accelerated from a stopped state, and thereafter travels at a substantially constant maximum speed.

In this case, the maximum speed of pallet 2 is
The greater the weight of the objects loaded on the conveyor, the lower the weight. That is, the weight detector 32 supplies a detection signal corresponding to the weight of the objects loaded on the pallet 2 to the voltage adjustment circuit 33, and based on this detection signal, the voltage adjustment circuit 33 adjusts the contactors 22,
The level of the voltage between the control line 20 and the conductor 21 detected via 23 is adjusted and applied to the coil _L1 . At this time, the voltage adjustment circuit 33 steplessly adjusts the level of the voltage applied to the coil _L1 so as to be proportional to the detection signal. As a result, when the weight of the transported object is relatively light, the voltage supplied to the coil L ₁ becomes E ₁ [V] in the acceleration/constant speed region X ₁ as shown in Fig. 2 A, and the transported object As the weight of the object increases, as shown in Figure 2 C, the coil
The voltage supplied to L ₁ decreases to E ₂ [V], E ₃ [V], and so on. As a result, the maximum speed of the pallet 2 is kept lower as the weight of the loaded objects increases.

Next, in the deceleration region X ₂ shown in Fig. 2A,
As the pallet 2 moves, the voltage PV detected from the resistance line portion 20b of the control line 20 and the conductor 21 linearly decreases from E ₁ [V] to 0 [V] as it approaches the station ST ₂ . Then, in order to follow this voltage characteristic, pallet 2 runs while gradually decreasing its average speed, and finally the station
Stop at ST ₂ .

In this way, by appropriately setting the voltage between _each station ST ₁ , _{ST 2 .} It can be moved sequentially.

In addition, in the above-mentioned embodiment, a case was explained in which the present invention was applied to a secondary ground type conveyance device using the LIM as a drive source, but the present invention is not limited to this, and it is also possible to apply it to a primary ground type conveyance device. Furthermore, in addition to using the LIM as the drive source, it is of course possible to apply the present invention to a conveyance device that uses a DC motor as the drive source.

"Effects of the Invention" As explained above, according to this invention, there is provided a driving means for moving the cart along the conveyance path, a control line provided along the conveyance path, and a predetermined potential applied to the control line. a potential setting means for setting the distribution; a contact provided on the trolley and slidably in contact with the control line; a speed detection means for outputting a speed detection signal according to the moving speed of the trolley; a weight detecting means for detecting the weight of the transported object loaded on the body; and adjusting and outputting the potential of the control line detected through the contactor according to the weight detected by the weight detecting means. an adjusting means for outputting a signal with a smaller signal value as the detected weight increases when the potential of the control line is constant; control means for turning on the driving means when the weight is large; a potential distribution is set appropriately on the control line by a potential setting means; and the trolley is moved in a running pattern according to the potential distribution and the weight of the object Since the vehicle is run, the following effects can be obtained.

The position sensor that was conventionally provided in each station becomes unnecessary, and the configuration is simplified.

Conventionally, in order to control the speed of a cart, a drive control device consisting of a large number of expensive thyristors and semiconductor elements such as power transistors was required, but since this is no longer necessary, the entire transport device can be constructed at a low cost. can do.

The running speed of the cart is limited according to the weight of the loaded object, and thereby the impact force applied to the object during acceleration and deceleration can be kept low.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of this invention, and FIG.
A graph showing changes in the voltage PV applied to the coil L ₁ and the voltage SV applied to the coil L ₂ as the coil L 1 moves, and FIG. 2B shows the drive voltage supplied to the primary side M of the LIM in the same embodiment Diagram to explain,
Figure 2C is a graph showing changes in the voltage PV applied to the coil _L1 and the voltage SV applied to the coil _L2 when the weight of the transported object increases in the same embodiment, and Figure 3I and (b) are a front view and a plan view showing the configuration of a conventional ground primary type conveyance device using a LIM as a drive source, and FIG. 3 (c) is a graph for explaining the traveling pattern of pallet 2 in the same conveyance device.
FIG. 4 is a perspective view showing the configuration of a secondary above-ground transport system using a conventional LIM as a drive source. M...Primary side of LIM (driving means), 2...Pallet (truck), 7...Secondary side conductor of LIM, 14...
...Track (conveyance path), 15...Power supply device, 16a~
16c...Feeding line, 18a-18c...Collector,
19... Voltage setting device (potential setting means), 20...
...Control wire, 20a...Conductor wire portion, 20b...Resistance wire portion, 21...Conductor wire, 22, 23...Contactor, 24
...Tachogenerator (speed detection means), 25...
...Relay, L ₁ , L ₂ ... Coil, 26 ... Fixed core, 27 ... Movable core, 28 ... Movable contact, 29
...Fixed contact, 30...LIM control circuit, 32...
...Weight detector (weight detection means), 33... Voltage adjustment circuit (adjustment means).

Claims (1)

[Scope of utility model registration request] a drive means for moving the cart along the conveyance path;
A control line provided along the conveyance path, a potential setting means for setting a predetermined potential distribution on the control line, a contact provided on the trolley and slidably in contact with the control line, and the trolley. speed detection means for outputting a speed detection signal according to the moving speed of the vehicle; weight detection means for detecting the weight of the transported object loaded on the trolley; A means for adjusting and outputting a potential according to the weight detected by the weight detecting means,
an adjusting means that outputs a signal with a smaller signal value as the detected weight increases when the potential of the control line is constant; and the driving means when the output signal of the adjusting means is larger than the speed detection signal. A conveying device comprising: a control means for turning on the controller.