JPS6399703A - Speed detector in linear motor type carrier device - Google Patents

Abstract

PURPOSE:To reduce a space occupied by a sensor, by a method wherein a detecting means, outputting a speed signal in accordance with the passing speed of respective slits of a slit plate only during a period when the slit plate, provided on a carrier, is detected, is provided in the title detector. CONSTITUTION:When light beams, generated by a light emission diode D1, are intercepted by the upper area UA of a slit plate 16, the potential of the collector of a phototransistor Tr1 becomes a H-level. When the light beams, generated by the light emission diode D2, are intercepted intermittently by the lower area LA of the slit plate 16, in which slits 16a are formed, the potential of the collector of the phototransistor Tr1 becomes H-level intermittently. The output terminal of an AND gate 18 becomes H-level intermittently in accordance with the intermittent H-level of the potential of the collector of the phototransistor Tr1 whereby the ON/OFF operations of the transistor Tr2 may be effected with a period in accordance with the moving speed of the slit plate 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a linear motor type conveying device used for conveying articles in factories, warehouses, etc., and particularly relates to a speed detection device for detecting the traveling speed of a carrier. .

"Prior Art" For example, a linear motor type conveyance device using a single-sided linear induction motor (hereinafter abbreviated as LIM) as a drive source is known as a conveyance means in a product assembly conveyance line or the like.

Figures 4 (a) and (b) are diagrams showing the external configuration of this type of linear motor type conveyance device. has four rotatable wheels 3.3. This is a carrier that is supported by and runs on a rail l, and objects to be transported are loaded onto this carrier 2. M, ~M. are arranged at predetermined intervals along the rail 1, and are responsible for generating a traveling magnetic field.
The primary coil of I M, 5, is attached to the underside of carrier 2, and the primary coil of L I M, ~Nll1
This is the secondary conductor of L I M, which is opposite to L with a gap below it. 6 is a slit plate attached to the side of the carrier 2, and a plurality of slits 6a, 6a, . . . are formed at equal intervals in the running direction of the carrier 2. P
, ~Pn are located on the sides of the rail l, and each primary coil M
, -M.

There are three carrier detection sensors arranged at a predetermined positional relationship. Each of these carrier detection sensors P
I'=P n is carrier 2 is connected to each primary coil ~1
．． It detects whether or not it exists on 〜〜1n,
It is constituted by a reflective photosensor, and when carrier 2 is detected, it outputs carrier detection signals 01 to Cn, respectively. In addition, 51 to sn are carrier detection sensors P.
, -Pn, respectively. These speed sensors S1 to Sn detect the passing speed of the carrier 2 as it passes over the primary coils M and 4n, respectively, as shown in FIGS. 5(a) and 5(c).
This is constituted by a transmission type photosensor in which a light emitting diode D and a phototransistor Tr are integrated into a U-shaped case. Then, the portion of the slit plate 6 in which the slits 6a, 6a, . . .
A speed signal SP, ˜SP, having a pulse frequency corresponding to the passing speed of the carrier 2 is outputted from. As shown in FIG. supplied to This speed signal selector 7 selects one of the speed signals 5Pl-8PnO,
Since only the speed signals corresponding to the carrier detection signals C1 to Cn are selected and supplied to the P/V (frequency/voltage) converter 8, for example, when the carrier detection signal C3 is supplied, the speed signals SP, is supplied to the F/V converter 8, and when the carrier detection signal C7 is supplied, a speed signal SP is supplied to the F/V converter 8.

The F/V converter 8 converts the pulse frequency of the speed signals SP, ~SPn supplied from the speed signal selector 7 into a voltage signal, and generates this voltage signal, that is, a speed detection signal of a voltage corresponding to the speed of the carrier 2. This is to supply Sa to the speed control device 9. The speed control device 9 adjusts each primary coil M 1 = so that the voltage of the speed detection signal Sa supplied from the F/V converter 8 matches the voltage of the speed setting signal sb supplied from the speed setter IO. It controls the three-phase AC (3φAC) voltage supplied to Mn, thereby performing speed feedback control. A solid state relay (S S
R)r(, -f'?n) are connected to each other, and these solid state relays R, -R, are controlled by the Nokens control device 11, respectively. Sequence control device +1 controls on/off of each solid state relay n, -rtn based on carrier detection signals C8 to Cn supplied from carrier detection sensors P l to P n, respectively, according to a preset procedure. .

For example, when carrier detection signal CI is supplied, solid state relay R1 is turned on, and when carrier detection signal C7 is supplied, solid state relay R is turned on.
Turn on 7.

In such a configuration, when the carrier 2 reaches the top of the primary coil M, a carrier detection signal C5 is output from the carrier detection sensor Sl, and at the same time,
Speed signal SP from speed sensor S.

is output, and this speed signal S)) is selected by the speed signal selector 7 and supplied to the F/V converter 8, which converts it into a voltage signal and generates the speed detection signal Sa.
It is supplied to the speed control device 9 as a signal.

On the other hand, the carrier detection signal CI is
1, the sequence control device 11 turns on the solid state relay R5.

Then, the speed control device 9 controls the three-phase AC voltage supplied to the primary coil M so that the voltage values of both the speed detection signal Sa and the speed setting signal sb match,
Thereby, the speed of the carrier 2 is accelerated to the speed set by the speed setting device 10. Next, when the carrier 2 passes over the primary coil M1, the carrier detection signal CI is no longer output from the carrier detection sensor P, and the solid state relay R1 is thereby turned off. Thereafter, the carrier 2 moves by inertia to the next primary coil M while decelerating slightly, repeats the same operation as described above, and is accelerated to the speed set by the speed setting device 10. In this way, each time the carrier 2 passes above each primary coil M1 to M,
3 supplied for each primary coil M + −M n
The voltage of the phase alternating current is controlled, thereby accelerating the carrier 2 to the speed set by the speed setting device IO.

"Problems to be Solved by the Invention" By the way, in the conventional linear motor conveyance device described above, the speed sensors S1 to Sn and the carrier detection sensors P and -pn had to be provided separately. The disadvantage is that the installation space is large and the installation work is complicated. Also, speed signals SP, -5 output from the plurality of speed sensors S, -S, respectively.
In order to process Pn with one F/V converter 8, it is necessary to provide a speed signal selector 7.
and each carrier detection sensor P, -pn must be connected with a signal line, which has the disadvantage of complicating wiring work and increasing installation cost.

This invention was made in view of the above-mentioned circumstances, and by integrating the speed sensor and carrier detection sensor, it is possible to minimize the installation space of the sensor, and
Furthermore, it is an object of the present invention to provide a speed detection device for a rear motor type conveyance device that simplifies wiring work and reduces installation costs.

"Means for Solving the Problems" This invention provides a linear linear system comprising a plurality of primary coils arranged along a running path of a carrier, and a secondary conductor facing the primary coils provided on the carrier. In the motor type conveyance device, the carrier is provided with a slit plate in which a plurality of slits are formed at equal intervals along the traveling direction of the carrier, and at a plurality of predetermined locations on the traveling path,
a detection means that outputs a speed signal corresponding to the passing speed of each slit of the slit plate only during a period in which the slit plate is detected; and a switching means that turns on/off according to the speed signal output from the detection means. Each switching means of each of these speed detection sensors is connected in parallel to a pair of common signal lines, and the detection signal outputted via each of the switching means is connected to the pair of common signal lines. The feature is that the signal is transmitted to the next speed signal processing means via the line.

"Function" Only during the period when the detection means is detecting the slit plate, a speed signal corresponding to the passing speed of each slit of the slit plate is output, and the speed signal output from this detection means is transmitted to each switching element and Since the signal is transmitted to the next stage speed signal processing means via a pair of common signal lines, unlike the conventional method, a carrier detection sensor for detecting carrier growth and a speed sensor for detecting the carrier speed are separately provided. Compared to the case where the device is installed, less installation space is required, the wiring work is simplified, and the installation cost is lower.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1A and 1B are diagrams showing the external configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the electrical configuration.

In FIGS. 1(A) and 1(B), 16 is a slit plate provided on the side of the carrier 2, and the vertical surface portion of the slit plate 16 is arranged in two stages, upper and lower, along the running direction of the carrier 2. When divided into strip-shaped areas UA and LA, the lower area LA has slots 16a, 16a, . . . formed at equal intervals along the running direction of the carrier 2, and the upper area UA includes , nothing is formed.

On the other hand, inside the U-shaped case arranged along the conveyance path, there are two light emitting diodes D and D2, and 69 lights emitted from each of these light emitting diodes D1 and D2. Optical filter phototransistor Tr+ and II
r2 has been installed. In this case, the light emitting diode F
The front axis I71 between the light-emitting diode D and the phototransistor Tr is blocked by the negative step area UA of the slit plate 16, and the optical axis between the light-emitting diode D and the phototransistor Tr is L, are arranged so as to be intermittently interrupted by the lower region LA of the slit '516.

Next, the electrical configuration of the speed detection sensor 20 having the previously described configuration will be explained.

As shown in FIG. 2, light emitting diodes D,,D.

Each cathode of is grounded, and each anode is connected to ↓Vcc via a resistor r. Furthermore, the emitters of the phototransistors T rl and T rv are grounded, and the collector of the phototransistor Tr+ is pulled up by a pull-up resistor r1 and connected to an AND gate 1.
The phototransistor Tr
The collector of t is pulled up by a pull-up resistor r, and is connected to the other input terminal of the AND gate 18. Further, the L[i terminal of the AND gate 18 is connected to the base of the output transistor 'Fr3, and the collector of this transistor i'rs is connected to the terminal T1.
The emitter is connected to terminal 1' and grounded.

The terminals T, W, and 'l'2 of the valley speed change detection sensor 20 are each connected in parallel to a pair of common signal lines 22.23, and F/' V
It is connected to input terminals T3 and T4 of converter 8.

Inside this I'/V converter 8, there are
A power supply 25 is provided, and a cathode of a photocoupler 24a is connected to a terminal T3, and an anode is connected to a terminal T4 via the power supply 25.

In the speed detection sensor 20 configured as above,
When the light emitted from the light-emitting diodes D, D, respectively reaches the phototransistors Tr+ and Trt, the potentials on the collector sides of the phototransistors Tr+ and Tr are both at the “[,” level (OV ).

Now, when the light emitted from the light emitting diode D1 is blocked by the upper area UA of the slit plate 16, the potential on the collector side of the phototransistor Tr becomes "H" level (about 10 V cc), and this Accordingly, carrier detection signals C, (or C2 to Cn) are output from the terminal Tc. In this way, during the period in which the light emitted by the light emitting diode D+ is blocked, the slits 16a, 16a in the lower area LA of the slit plate 16 are
,... are formed, the light emitting diode D
When the light emitted from , is intermittently interrupted, the potential on the collector side of the phototransistor Trt intermittently changes to
1” level (Habo+V cc), and accordingly,
The output terminal of the AND gate 18 is intermittently set to the "0" level, and as a result, the transistor Tr3 is turned on/off at a period corresponding to the moving speed of the slit plate 16 χ1.

iron, each speed detection sensor 20, 20. When the slit plate 16 is detected by any one of the transistors Tr3 and the transistor Tr3 is turned on/off, this on/off signal is sent to the F/V converter 8 via the common signal line 22.23.
As a result, the slit plate 16 is
A speed signal S■) with a pulse frequency corresponding to the moving speed of
-9F'n is transmitted to the F/V converter 8 side.

When the speed detection sensor 20 having such a configuration is applied to a linear motor type conveyance device, as shown in FIG. They may be connected by common signal lines 22 and 23, and each speed detection sensor 20 and the Noken control device 11 may be connected by a signal line.

According to the embodiment described above, the speed detection sensor 20 of Il[Aj has the function of detecting the speed of the carrier 2 as well as the function of detecting the presence or absence of the carrier 2, so that , the carrier detection sensors p, -pn(
(see FIG. 6) is no longer necessary, and the installation space for the sensor can be minimized. Moreover, as shown in FIG. 3, since each speed detection sensor 20 and the F/V converter 8 can be connected only by a pair of signal lines 22 and 23, wiring work is extremely simplified.

In addition, in the above-mentioned embodiment, assuming that the carrier 2 is traveling in one direction, one is used for speed detection.
The explanation has been given using an example in which a pair of light emitting diodes D and a phototransistor Trz are provided, but if the traveling direction of the carrier 2 is reversible, the slits 16a, 16a, . . .
Two sets of light emitting diodes D 2 , D 2 so as to output a signal having a phase difference of 90° with respect to the pitch of
and phototransistors Trt, Trt may be provided.

"Effects of the Invention" As explained above, according to the present invention, the carrier is provided with a slit plate in which a plurality of slits are formed at equal intervals along the running direction of the carrier, and the running path of the carrier is At a plurality of predetermined locations, detecting means outputs a speed signal corresponding to the passing speed of each slit of the slit plate only during the period of detecting the slit plate, and a detecting means that outputs a speed signal according to the passing speed of each slit of the slit plate, and a speed signal output from the detecting means Each speed detection sensor is provided with a switching means that turns on/off, and the switching means of each speed detection sensor is connected in parallel to a pair of common signal lines, and the detection output via each switching means is connected in parallel to a pair of common signal lines. Since the signal is transmitted to the speed signal processing means at the next stage through the pair of common signal lines, a sensor for detecting the presence or absence of a carrier and a sensor for detecting the speed of the carrier are separately provided. The installation space for the sensor can be reduced compared to the case where the sensor is installed, and since the speed signal is transmitted through a pair of common signal lines, wiring work is extremely simplified and installation costs are reduced. You can get that effect.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are side and front views showing the external configuration of an embodiment of the present invention, Figure 2 is a circuit diagram showing the electrical configuration of the embodiment, and Figure 3 is the same embodiment. A block diagram showing the configuration when the example is applied to a linear motor type conveyance device,
Figures 4 (a) and (b) are side and front views showing the external configuration of a conventional linear motor type conveyance device, and Figures 5 (a) and (b) are views showing the external configuration of a conventional linear motor type conveyance device. FIG. 6 is a block diagram showing the electrical structure of a conventional linear motor type conveyance device. 2...Carrier, 8...F/V converter (speed signal processing means), 16...Slit plate, 16a...Slit, UA... ...Upper area, LA...Lower area, K...
Case, DI, D2... Light emitting diode, Try, Try... Ph+-transistor,
18...AND gate, Tr3...transistor (switching means), 20...speed detection sensor, 22, 23...common signal line, 2
4... Photo converter, 25... Power supply.

Claims (1)

[Claims] In a linear motor type conveyance device, a plurality of primary coils are arranged along a traveling path of a carrier, and a secondary conductor facing the primary coil is provided on the carrier,
The carrier is provided with a slit plate in which a plurality of slits are formed at equal intervals along the running direction of the carrier, and a slit plate is provided at a plurality of predetermined locations on the running path only during the period when the slit plate is detected. , a speed detection sensor consisting of a detection means that outputs a speed signal according to the passing speed of each slit of the slit plate, and a switching means that is turned on/off depending on the speed signal output from the detection means, Each of the switching means of each of these speed detection sensors is connected in parallel to a pair of common signal lines, and the detection signal outputted through each of the switching means is transmitted to the speed signal processing means of the next stage via the pair of common signal lines. A speed detection device for a linear motor type conveyance device.