JPS62201714A - Positioning stopper - Google Patents

Abstract

PURPOSE:To make a truck stoppable promptly owing to such restoring force that describes a hysteresis loop, by superposing the specified voltage (current) corresponding to a vibrating direction of the conveying truck on the preset bias voltage (current), and making a stopping electromagnet so as to be excited. CONSTITUTION:When a velocity direction of a conveying truck 11 is a sense of right and positive, a controller 15 feeds an electromagnet 13 with voltage V0+V1 and an electromagnet 14 with bias voltage V0, respectively, so that attraction of the electromagnet 13 is increased, whereby composite restoring force (f) shifts to a negative direction from a zero point, and damping force acts on vibrations in the truck 11. Next, at that point that the truck 11 is fully deflected in the positive direction, the velocity direction is turned over, coming to the negative direction, whereby the controller 15 feeds the electromagnet 13 with the bias voltage V0 and the electromagnet 14 with the voltage V0+V1, respectively, so that attraction of the electromagnet 14 is increased, and the composite restoring force (f) is shifted to the positive direction from the zero point, thus the damping force acts on vibrations in the truck 11. Thus, the damping force acts on either of vibration directions so that the vibration is damped, and the truck 11 and the restoring force (f) are focused to zero while describing a hysteresis curve, thus it comes to a stop at a spot of displacement x=0.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a conveyance device for conveying articles in a factory or the like, and in particular, the present invention relates to a conveyance device for conveying articles in a factory or the like, and in particular, a conveyance cart that moves with almost no frictional braking is moved to a predetermined position on a conveyance path. The present invention relates to a positioning and stopping device that can be stopped at a certain position in a short time.

[Prior Art] In this type of conveyance device, it may be necessary to accurately position and stop the conveyance cart at a station provided on the conveyance path in order to load, unload, or process objects to be conveyed.

FIG. 6 is a longitudinal sectional view showing an example of such a positioning and stopping device. In this figure, a secondary iron core 2 is fixed to the lower surface of a transport vehicle l.

On the other hand, on the conveyance path 3 side, a primary iron core 4 is arranged opposite to this secondary iron core 2 . Then, when the transport vehicle 1 reaches the stop position, by energizing the coil 5 wound around the primary iron core 4, the secondary iron core 2 is attracted to the primary iron core 4, and the transport vehicle 1 can be stopped at a predetermined position.

FIG. 7 is a graph showing the relationship between the displacement X of the transport vehicle 1 from the stop position and the restoring force r when the transport vehicle 1 is stopped. As can be seen from this figure, when the displacement X is positive, a negative restoring force f acts, and when the displacement
works. Therefore, the transport vehicle l vibrates around the displacement x=0 (equilibrium point), and ultimately comes to a stop at this equilibrium point while being affected by frictional force, air resistance, eddy current resistance, etc.

This type of positioning and stopping device can apply braking force to a moving object and stop it without contact, so compared to devices that use mechanical friction, there is no risk of dust generation and maintenance is easier. There are advantages.

Therefore, if such a positioning and stopping device can be incorporated into a magnetically levitated conveyance device driven by a linear induction motor, a conveyance device that can support, drive, and brake the conveyance vehicle without contact can be realized. This makes it extremely convenient for use in clean rooms where the generation of dust is extremely difficult.

[Problems to be Solved by the Invention] However, when the above-mentioned non-contact stopping device is incorporated into a magnetically levitated or air levitated conveyance device, the following inconveniences occur. Incorporation into the system has not been realized.

In other words, when the transport vehicle is supported by wheels, etc., an appropriate frictional force exists between the transport vehicle and the transport path, so when the above-mentioned positioning and stopping device is incorporated, this frictional force acts as a vibration damping force. , the transport vehicle can be stopped in a relatively short time. However, when it is incorporated into a magnetic levitation type conveyance device or the like, it takes a long time to stop because no mechanical frictional force is exerted between it and the conveyance path.

This invention was made against this background, and is incorporated into a magnetic levitation type or air levitation type conveyance device, etc.
It is an object of the present invention to provide a positioning and stopping device that can stop a transport vehicle within a short time.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a positioning stop device that stops a conveyance cart moving along a conveyance path at a predetermined stop position, which is configured in a non-contact manner. consisting of a primary side and a secondary side, one of which is attached to the stop position side and the other to the transport vehicle side, and
a plurality of electromagnets having different attachment intervals in the conveyance direction on the stop position side and attachment intervals in the conveyance direction on the conveyance vehicle side;
a detecting means for detecting the direction of the vibration speed near the stop position of the conveyance vehicle; 1
and control means for supplying damping force to two primary sides and generating a damping force.

[Function] According to the above configuration, a restoring force in the negative direction is applied when the vibration speed of the transport vehicle is positive, and a restoring force in the positive direction is applied when the vibration speed is negative. It is possible to quickly stop the conveyance vehicle while creating a hysteresis loop as shown by the broken line in FIG. Further, by adjusting a constant bias voltage (or bias current) supplied to a plurality of electromagnets, it is possible to finely adjust the stopping position.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams showing the configuration of an embodiment of the present invention. In these figures, 11 is a transport vehicle;
2 is near the stop position. Near this stopping position! In 2,
Primary side cores 13a and 14a of a pair of electromagnets 13 and 14 are arranged at a distance of 121 in the conveyance direction. The primary side iron core 13a.

14a has a substantially U-shaped cross section and is arranged with the opening facing upward, and excitation coils 13b and 14b are wound around the lower part.

On the other hand, two electromagnets 13 and 14 are mounted on the lower surface of the transport vehicle 11.
The next iron cores 13c and 14c are e2 (≠IJI) in the conveying direction.
) are installed at a distance of The secondary iron core 1
3c and 14c are in the shape of a rectangular parallelepiped, and can be moved through the openings of the primary cores 13a and 14a when the carrier vehicle 11 moves.

The coils +3b and +4b are connected to the output end of the control device 15. This control device 15 controls the coils 13b and 14b based on the speed signal output from the speed detector 16.
It separately controls the supply voltage to the

Here, the speed detector 16 consists of a long slit plate attached to the side of the transport vehicle, a pair of photosensors provided on the ground side sandwiching this slit plate, and the speed based on the output of the photosensor. The slit plate has two lines of vertical slits with different phases horizontally arranged on the side, and these are independently detected by the pair of photosensors. The speed direction of (2) is determined.

On the other hand, the control device 15 has a zipper function and controls the DC voltage supplied from the power source 17 based on the output (speed direction signal) of the speed detector 16. That is, the control device 15 includes an adder that adds a constant voltage Vt to the constant bias voltage vO according to the speed direction signal;
A triangular wave generator, a comparator that compares the triangular wave output from the triangular wave generator with the output of the adder, and turns on/off the DC voltage supplied from the power supply 17 using the output of the comparator as a gate signal. It is composed of PET.

Next, the operation of this embodiment will be explained with reference to FIGS. 3 to 5.

First, in order to facilitate understanding, the state when the same constant voltage is applied to the electromagnets 13 and 14 will be explained with reference to FIG.

FIG. 3 shows the relationship between the displacement X and the restoring force r when the transport vehicle 11 is displaced from the stop position. In this figure, displacement X=O is the position shown in FIG.

That is, the primary iron core 13a.

This is the position where the midpoint of 14a and the midpoint of secondary cores 13c and 14c coincide. When the displacement X=0, the primary core 13a of the electromagnet 13 attracts the secondary core 13c to the left in FIG. 2, that is, in the negative direction. Further, the primary core 14a of the electromagnet 14 attracts the secondary core 14c to the right in FIG. 2, that is, in the positive direction. In this case, the positive and negative suction forces (restoring forces) become equal, and the restoring force f applied to the transport vehicle 11 becomes zero.

When the transport vehicle If is displaced in the positive direction from this position, the displacement X becomes positive, the restoring force in the negative direction by the electromagnet 13 gradually increases, and the restoring force in the positive direction by the electromagnet 14 gradually weakens. As a result, a composite restoring force r (< o ) as shown by the broken line in FIG. 3 acts on the transport vehicle II, and the transport vehicle 11 is pulled in the negative direction. On the other hand, a transport trolley! When summer is displaced from the position of displacement x = 0 in the negative direction,
The attractive force of the electromagnet 13 weakens, and the attractive force of the electromagnet 14 increases. As a result, the carriage 11 is pulled in the forward direction. In other words, the transport vehicle 11 vibrates around the displacement X=0.

Next, the operation of this embodiment will be explained with reference to FIG.

FIG. 4 shows the restoring forces of the electromagnets 13 and 14 and the overall restoring force obtained by combining these forces, with the former shown by a solid line and the latter by a broken line. Further, the arrow in the figure indicates the speed direction, and the symbol VO indicates that the electromagnet 13, 14 is excited with a predetermined bias voltage VO (constant voltage). Furthermore, the code vo+vt is the electromagnet 1
3°14 indicates that the magnet is excited by a voltage VO+V1 obtained by adding a constant voltage Vt to the bias voltage VO.

Note that this constant voltage Vt is a positive voltage determined empirically.

In this figure, when the speed direction of the transport vehicle 11 is positive (that is, the arrow points to the right), the control device 15 controls the electromagnet 13.
A voltage vo+V1 is supplied to the electromagnet 14, and a bias voltage VO is supplied to the electromagnet 14. As a result, the attractive force of the electromagnet 13 increases, the resultant restoring force deviates from the zero point in the negative direction as indicated by the broken line La in the figure, and a damping force acts on the vibration of the transport vehicle II.

Next, the transport trolley l! When the velocity swings completely in the positive direction, the velocity direction reverses and becomes negative. At this time, the control device 15
A bias voltage vO is supplied to the electromagnet 13, and the electromagnet 14
A voltage VO+Vl is supplied to. As a result, the electromagnet 14
The suction force increases, the resultant restoring force r deviates from the zero point in the positive direction as indicated by the broken line Lb, and a damping force acts on the vibration of the transport vehicle 11.

In this way, the damping force acts regardless of the direction of vibration of the transport vehicle 11, so the vibration is gradually attenuated, and the transport vehicle l and the restoring force r converge to zero while drawing a hysteresis loop. In other words, the transport vehicle 11 should immediately stop at the point where the displacement y=0. In this case, energy corresponding to the area of the hysteresis loop is consumed by the electromagnet 13, the control device 15, and the like.

FIG. 5 is a graph showing the stopping positions when different constant voltages are applied to the electromagnets 13 and 14. in this case,
The excitation voltage of the electromagnet I4 is higher than the excitation voltage of the electromagnet 13. As a result, the entire restoring force r shifts to the right from the zero point, as shown by the broken line, and the transport vehicle 11 stops at point P in the figure.

In this way, by controlling the excitation voltage applied to the electromagnets 13, 14, it is possible to finely adjust the stop position. This is based on the installation interval Qt of primary side cores 13a and 14a and 2
This is the effect of differentiating the installation interval Q2 of the next cores 13c and 4c, and such an effect cannot be obtained when f2112.The reason is that when (1+ = Q2), the displacement x = 0 is always This is because it stops.

In addition, in the above embodiment, the installation interval of each iron core (1, (
! 2, (11>&2,!: L taka, this is good for the opposite direction.Also, the primary side of the electromagnet may be attached to the transport vehicle II side.Furthermore, with a constant voltage corresponding to the direction of the vibration speed, Instead of controlling, control may be performed using a constant current corresponding to the direction of the vibration speed.

[Effects of the Invention] As explained above, the present invention is capable of exciting a stop electromagnet by superimposing a constant voltage or a constant current corresponding to the vibration direction of the transport vehicle on a constant bias voltage or bias current. , it is possible to obtain the resilience to draw a hysteresis loop. Thereby, the carrier can be quickly stopped.

Furthermore, by adjusting the bias voltage (current) supplied to each electromagnet, the stopping position can be freely finely adjusted. Thereby, the stop position at the time of initial setting and the stop position during operation can be freely finely adjusted.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, and FIG.
The figure is a side view of the same example, Figure 3 is a graph showing the relationship between displacement and restoring force when a constant voltage is applied to the electromagnets 13 and 14, and Figure 4 is a bias voltage with a constant voltage corresponding to the vibration direction. A graph showing the relationship between displacement and restoring force when the electromagnets 13 and 14 are excited by superimposing the voltage, Figure 5 is the electromagnet 13.
．． 14 is a graph showing the state when the stopping position is finely adjusted by changing the constant voltage applied to It is a graph showing the relationship between displacement and restoring force in the positioning and stopping device. fI... Transport vehicle, 12... Near stop position, 13° 14... Electromagnet, 13a, 14a
...Primary side iron core, 13b, 14b...
Coil, 13c, 14c... Secondary iron core, t6
... Speed detector, 17 ... Control device. Figure 2 District

Claims (3)

[Claims] (1) A positioning stop device that stops a conveyance cart moving along a conveyance path at a predetermined stop position, which consists of a primary side and a secondary side configured in a non-contact manner, one of which stops the above-mentioned stop position. a plurality of electromagnets, one of which is attached to a position side, and the other is attached to the conveyance vehicle side, and the attachment intervals in the conveyance direction on the stop position side are different from the attachment intervals in the conveyance direction on the conveyance body side; and a plurality of electromagnets in the vicinity of the stop position of the conveyance vehicle. detection means for detecting the direction of the vibration velocity in the vibration velocity, and a constant voltage or constant current corresponding to the direction of the vibration velocity is superimposed on a predetermined bias voltage or bias current and is supplied to the primary side of at least one of the electromagnets. and a control means for generating a damping force. (2) The positioning and stopping device according to claim 1, wherein the stopping position of the carrier vehicle is finely adjusted by adjusting the bias voltage or bias current. (3) The positioning and stopping device according to claim 1, characterized in that instead of generating the magnetic field by supplying the bias voltage or bias current, a magnetic field generated by a permanent magnet is used.