JPH0374109A - Carrier employing linear motor - Google Patents

Abstract

PURPOSE:To reduce the energy consumption without extending the total carrying time by performing acceleration of carrying object previously in the constant speed region at each preceding station. CONSTITUTION:At first, positive phase full excitation signals are fed to linear motor coils 10, 10, 10 at a work station ST3 in order to accelerate a pallet P. Then it is judged whether a second work station ST2 has reached to the constant speed start point based on constant speed start pulses fed from a linear motor controller 32A. Upon reaching to the constant speed start point, the pallet P is carried with a constant speed and constant speed start pulses are fed to a linear motor controller 32B. Thereafter, it is judged whether the carrying speed has reached to the deceleration start point. Upon reaching to the deceleration start point, deceleration control is performed through negative phase excitation such that the pallet P is stopped at a predetermined point.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a conveying device using a linear motor.

(Prior Art) A conveyance device that uses a linear motor to carry out tact conveyance between a plurality of stations is known.

In such systems, it is desirable to start each carrier in perfect synchronization to avoid collisions between the carriers transporting the articles; During deceleration, the required energy (consumed energy) is superimposed and becomes considerably large.

For this reason, for example, as shown in Japanese Patent Application Laid-Open No. 60-237803, a method is used in which the carrier starts in the order in which transport requests are received, and after completing travel to the destination station, the carrier that received the next transport request starts traveling. ing.

In such a system, because the transport efficiency is low, there is a traveling area between the starting station of the carrier that starts the launch and the destination station that includes the starting stations and stopping stations of other carriers that have already started. It has been proposed to provide means for confirming that the carrier has not been launched, and to launch the carrier after confirming that the running area of the carrier that is about to start does not overlap with the running area of other carriers that have already started.

(Problem to be Solved by the Invention) However, in such a device, the carrier is started only after confirming that the travel area of the carrier that is about to start does not overlap with the travel area of other carriers that have already started. As a result, the time required for transporting the entire article increases, resulting in poor efficiency.

The present invention has been made in view of the above, and an object of the present invention is to provide a conveyance device using a linear motor that can reduce energy consumption without prolonging the time required for conveying the entire article.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a plurality of stations, each station is provided with a linear motor including a linear motor coil and a reaction member, and the linear motor In an apparatus that sequentially transports objects between the plurality of stations using a motor, there is provided a constant speed area detection means for detecting a constant speed area of the article transport at each station, and a constant speed area detection means for detecting the constant speed area of the article transport at each station, and a constant speed area detection means for detecting an output of the constant speed area detection means for detecting a constant speed area of the article transport at each station. The present invention is characterized in that it has an acceleration control means for performing acceleration for transporting the article in a constant speed range for transporting the article at the previous station of the specific station.

(Function) At each station, acceleration for transporting the article is performed in the constant speed range for transporting the article at the previous station.

(Example) Embodiments of the present invention will be described below based on the drawings.

Figures 1 to 3 show a case where a conveyance device A using a linear motor is applied to a vehicle assembly line as an embodiment of the present invention, and this conveyance device A carries pallets P as objects to be conveyed. The body B is transported between adjacent work stations within a certain period of time with the body B placed thereon. The pallet P has a number of rollers 2, 2. It is supported by a roller conveyor 3 consisting of... and is conveyed while sliding on the roller conveyor 3.

Inside both of the supporting members 1.1, a large number of linear motor coils 10.10. Two stator rows 11, 11 consisting of... are arranged in parallel. Each stator row 11 above
Two guide rails 12 extending in the transport direction are provided on both sides of the
．． 12, and a plate member 13 is disposed movably engaged with the guide rail 12.12. On the lower surface of the plate member 13, a plate made of, for example, iron and aluminum is disposed. A reaction member 14 as a layered movable member is integrally attached. Therefore, the reaction member 14 is provided so as to be movable along the stator row 11 under the guide of the guide rail 12. Note that the engagement between the guide rail 12 and the plate member 13 does not restrict upward displacement of the plate member 13.

Furthermore, the plate member 13 is attached to the back surface of the pallet P via an attachment member 15.

Thus, the reaction member 14 provided in each stator row 11 acts on each stator row 11 by the thrust generated by the electromagnetic action between each stator row 11 and each linear motor coil 10. along the downstream side in the conveying direction (first
The pallet P with the body B placed thereon is conveyed sequentially between adjacent work stations within a certain period of time. The coil 10 and the reaction member 14 constitute a linear motor 23, and one linear motor 23 is provided for each work station.

FIG. 4 shows a block configuration of a control section that controls the linear motor 23.

Each work station ST,,s'r2. ST3.

STa has 3 linear motor coils 10.10.10.
Each linear motor coil 10,
10.10 is phase control section (amplifier) 31.31.31
Through the linear motor controller 32A, 32B, 3
Phase control for excitation is performed at 2C.

Each of the above work stations STI, s'r:, Sr3
, Sr1 linear motor controller 32A.

32B and 32C are linked to a station controller 33, and the station controller 33 monitors the status of the pallet P at each work stage ST+, ST2, ST3°Sr1, and controls each station STI, Sr1.
r1. Speed control of the linear motors 23 of Sr3 and Sr1 is performed via linear motor controllers 32A, 32B, and 32C. That is, when the pallet P on which the body B is placed is sequentially fed to each work station by the linear motor 23, there is a gap between one adjacent work station, for example, the first work station ST+ and the second work station ST in FIG. , each linear motor coil 10 is excited under the control of the station controller 33, and the thrust generated in the reaction member 14 by the electromagnetic action between the linear motor coil 10 and the action member 14 causes the body B A pallet P, on which is placed a . In other words, the speed change is in the acceleration region Z
1, a constant speed area Zl, and a deceleration area Z3.

34a, 34b, 34c, and 34d are speed sensors (
For example, a pulse generator), the speed sensor 34a,
Speed signals from 34b, 34c, and 34d are input to linear motor controllers 32A, 32B, and 32C.

Thus, for example, the second work station Sr2 is controlled by the linear motor controller 32B as shown in FIG. Note that this control starts when the first work station ST+ passes the constant speed point and enters the constant speed region Zl (see FIG. 5).

First, when starting, a positive phase full excitation signal is output to the linear motor coils 10, 10.10 of the work station Sr3 for acceleration at startup (step S2). Then, speed control is performed to accelerate the pallet P (step S2). Thus, an acceleration control means 32a is configured that performs acceleration for transporting the article in a constant speed range for transporting the article at the work station located at the front position.

Thereafter, in step S3, the second work station ST,
It is determined whether or not the point has reached the constant speed start point. Whether or not the constant speed start point has been reached is determined based on the output of the constant speed start pulse from the linear motor controller 32A.

If the constant speed start point has not been reached, the speed control in step S2 is continued, and if the constant speed start point has been reached, the process moves to step S4, where the pallet P is made to travel at a constant speed, and the linear motor controller A constant speed start pulse is output to 32B. In this way, constant speed area detection means 32b for detecting the constant speed area of article conveyance is configured.

Then, after running at a constant speed, it is determined whether the deceleration start point has been reached (step S2). If it is not the deceleration start point, the process returns to step S4 and continues constant speed travel, while if the deceleration start point is reached, the process moves to step S6, and reverse-phase excitation is performed so that the pallet P stops at a predetermined stopping point. Deceleration control is performed and the process ends.

With the above configuration, as shown in FIG. 7, for example, the second work station ST! When the first work station ST at the front position reaches the constant speed traveling start point U+ for transport, acceleration for transporting the pallet P which is the object to be transported is started, and the first work station ST at the front position work station ST and a subsequent second work station S
This will avoid overlapping the acceleration region with r2. Similarly, the second work station ST
, when the constant speed traveling start point U2 for conveyance is reached, the third work station Sr3 starts accelerating the pallet P, and the third work station ST3 starts accelerating the pallet P.
When the constant speed traveling start point U3 for conveyance is reached, acceleration of the pallet P starts at the fourth work station STJ.

Therefore, in terms of the entire transport line, the transport operations at each work station are partially synchronously performed, so that the time required to transport the pallet P (object to be transported) is shortened.

In addition, by doing this, the possibility that the acceleration regions that consume the most energy will return to IJL is reduced, and as a result, the possibility that the deceleration regions overlap each other and the acceleration region and the deceleration region overlap. The total amount of energy consumed is also significantly smaller than when the operations at each station are completely synchronized. Specifically, the cycle time is 5
If the cycle time is 0 sec, the current consumption will be 100 A (see Figures 8 and 9), but in the case of complete synchronization, it will be 2700 A to 300 A with a cycle time of 48 sec, and in the case of partial synchronization of the present invention, Current consumption is significantly smaller than in the case of complete synchronization. Note that the above numerical values are for the case of five work stations.

It should be noted that the present invention is not limited to the above embodiments, but includes various other modifications.

For example, in the above embodiment, the present invention is applied to a case where the linear motor 23 is configured with the linear motor coil 10 as a stator and the reaction member 14 as a mover, but the present invention is not limited to this. The present invention can be similarly applied to the case where the linear motor 23 is constructed by disposing the reaction member 14 along the conveyance line to serve as a stator, while disposing it on the plate member 13 side to serve as a movable element.

Further, in the above embodiment, the case where the transport device A is applied to a vehicle assembly line is shown, but the present invention is not limited to this, and it goes without saying that it can be applied to the case of transporting other objects to be transported.

(Effects of the Invention) As described above, according to the conveying device using the linear motor of the present invention, acceleration for conveying articles at each station is performed in the article conveying constant speed range of the previous station. Energy consumption can be reduced without prolonging the time required for transporting objects throughout the apparatus.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a side view of the conveying device, FIG. 2 is a plan view of the same, and FIG.
4 is a block diagram of the control unit that controls the linear motor, FIG. 5 is a diagram showing speed changes during conveyance, FIG. 6 is a flowchart showing the flow of control, and FIG. 7 is a diagram showing each station. Figure 8 showing the relationship between speed changes in
The figure shows changes in current consumption for five work stations, and FIG. 9 shows changes in current consumption across the entire transport line. Figure 10 is a diagram showing changes in current consumption when transport operations are completely synchronized for five work stations.
FIG. 1 is a diagram showing changes in current consumption in the entire transport line when the transport operations are completely synchronized. A...Transfer device P...Pallet lO...Linear motor coil 14...Reaction member 23...Linear motor 32... ...Linear motor controller 32a...
... Acceleration control means 32b ... Constant speed range detection means is 2) 5th Fig. 7 Fig. 6 STs] Fig. 8 T5 T1-Tail 10 (2)

Claims (1)

[Claims] (1) In a device having a plurality of stations, each station being provided with a linear motor consisting of a linear motor coil and a reaction member, and using the linear motor to sequentially transport objects between the plurality of stations. , a constant speed area detecting means for detecting a constant speed area for transporting articles at each station; and a constant speed area detecting means for detecting the constant speed area for transporting articles at each station; 1. A conveyance device using a linear motor, characterized in that it has an acceleration control means that performs the conveyance in a constant speed range.