JPH0818193B2 - Work transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is applied to, for example, a work transfer device applied to an assembly line, in which the work transfer device has a positioning function. It is intended to improve.

(Prior Art) Conventionally, as this type of transfer device, a pallet carrying a work is transferred by a conveyor, and after forcibly stopping the pallet at each station, a positioning member such as a pin is operated to position and fix the pallet. It is publicly known that the parts are assembled to the work by an inserter or an assembly robot (literature unknown).

(Problems to be Solved by the Invention) As described above, in the conventional apparatus, the pallet at each work station is fixedly positioned by the mechanical engagement of the positioning member. Therefore, the actual work such as assembly of parts cannot be performed until the pallet's localization fixing is completed, and after the actual work is completed, the pallet's localization fixing must be released before proceeding to the next process. The pallet cannot be moved. In other words, it is unavoidable that a dead time is required for fixing and releasing the fixed position of the pallet for each station, and the dead time becomes a problem as the actual work speed and the transfer speed between work stations are improved. It has become to.

Further, since the parts are assembled while the pallet is fixedly positioned, the inserter and the assembly robot all perform positioning of the assembled parts in space. Therefore, there is no choice but to increase the degree of freedom of movement required by an actual work device such as an assembly robot, and the greater the degree of freedom of movement, the more time it takes to perform the work, making it difficult to increase the actual work speed. But there was a problem. Furthermore, in order to support small-quantity production of each product type, an assembly robot with a high degree of freedom of movement will be installed at all work stations to increase the volatility of work at each station. I was dissatisfied with the fact that the cost was high and the facility cost was high.

This invention solves the above-mentioned problem and eliminates the dead time required for the localization fixing and the fixing release by performing the localization fixing of the pallets at the work station by an electromagnetic force, and at the same time improves the transport efficiency. The purpose is to improve the accuracy of localization fixation.

Another object of the present invention is to allow the pallet to be reciprocally driven within a certain range in each work station, and to position the pallet itself so that it can be displaced relative to the actual work device, so that the operation of the actual work device can be freely performed. The purpose is to reduce the degree of work, improve the work speed, and at the same time reduce the equipment cost.

(Means for Solving the Problems) Therefore, according to the present invention, the pallet in the work station is fixed in a fixed position and reciprocally driven within a certain range by a linear motor to improve the transfer efficiency and to reduce the actual work speed. Achieve improvements, etc.

Concretely, as shown in FIG. 1, the solution means of the invention of claim (1) is a fixed conveying path (1) and a work (which is movably guided and supported by the conveying path (1). A pallet (2) for transferring W), a plurality of work stations (S) arranged along the transfer path (1), and a plurality of work stations (S) provided on the transfer path (1). ,
A stator (10) constituting a linear motor, a mover (11) provided on the pallet (2) corresponding to the stator (10) and constituting a linear motor, and the transport path (1). A pallet sensor (23) provided for each work station (S) to detect the passage of the tip of the pallet (2), a transport path (1) corresponding to each work station (S), and the pallet. A position sensor (24) provided between the pallet (2) and the pallet (2) for detecting the absolute position of the pallet (2).
And a braking operation command signal to the stator (10) to receive the output of the pallet sensor (23) and forcibly stop the pallet (2).
And a controller (25) for controlling the stator (10) so as to stop the mover (11) of the pallet (2) at the origin by receiving the output of 4). In this case, in the invention of claim (2), in order to perform the localization fixation with high accuracy, the stator (10) is used as the linear motor and the stator (10) is connected to the electromagnet (1
In 2) and 13), it is preferable to use a linear pulse motor in which the mover (11) is composed of a motor rack on the secondary side. A linear motion type resolver is used as the position sensor (24).

(Operation) As a result, according to the inventions of claims (1) to (3),
An electromagnetic force is applied between the stator (10) provided on the transfer path (1) and the mover (11) provided on the pallet (2) to localize the pallet (2) at each work station (S). Since the fixing is performed by the electromagnetic force, the positioning, the fixing, and the releasing of the fixing can be instantaneously performed, and the series of transfer operations can be efficiently performed without wasting time.
In particular, if a linear pulse motor is used as in claim (2), the localization fixation can be performed more accurately. Further, by controlling the magnetic field state of either or both of the stator (10) and the mover (11), the pallet (2) can be reciprocally driven via the mover (11).
By displacing the pallet (2) with respect to the actual work device, the degree of freedom of operation of the actual work device corresponding to this displacement direction can be reduced, and the actual work speed and the work efficiency can be improved accordingly. Becomes At the same time, the structure of the actual work device can be simplified, and the cost required for the entire line can be reduced.

At this time, when the pallet sensor (23) detects passage of the tip of the pallet (2), a braking operation command is issued from the controller (25) to the stator (10), and the pallet (2) is forcibly stopped. At this time, the mover (11) is
0), if there is a deviation from the preset origin position, the deviation is read by the position sensor (24),
The stator (10) is controlled so that the mover (11) stops at the origin. As a result, the mover (11) can be stopped at the origin without displacement, and the pallet (2) can be fixed in a fixed position with high accuracy.

(Embodiment) FIGS. 1 to 3 show an embodiment in which the present invention is applied to an assembly line.

In FIG. 2, the assembly line includes a transport path (1) arranged in an endless loop, a plurality of pallets (2) movably guided and supported on the transport path (1), and the transport path (1). 1) consists of a number of work stations (S), etc. arranged at predetermined intervals, and a pallet (2) having a work (W) mounted and fixed on the upper surface moves along the transport path (1), At the station (S), the parts (P) are assembled and processed. Each station (S) has a parts feeder (3) depending on the work content.
An actual working device such as an assembling robot (4) or a work (W) mounting device is provided.

The transport path (1) includes a fixed frame (5),
It is composed of a pair of rails (6), (6) provided on both sides of the upper end of the frame (5), and both rails (6), (6)
Is driving the pallet (2). Pallet (2)
Is a base plate-shaped main body (2a), four rollers (7) rotatably supported on both sides of the main body (2a), and the main body (2
Four rollers (8) rotatably supported on the underside of a)
And a work holding mechanism (not shown). Of the two rollers (7) and (8), the former roller (7) rolls on the upper surfaces of the rails (6) and (6), and the latter roller (8) rotates to the rails (6) and (6). Rolling on the inner surface of the pallet to move the pallet (2) along the rails (6) and (6), and at the same time, the running posture of the pallet (2) by the cooperative action of both rollers (7) and (8). Is designed to be precise.

In order to fix the pallet (2) at each station (S) or move it relative to the assembling robot (4), a driving means applying the principle of a linear motor is provided with a conveying path (1) and each pallet (2). It is provided in and. Specifically, the stator (10) constituting the linear pulse motor is arranged and fixed on the base wall (5a) of the frame (5) corresponding to each work station (S), and the main body of each pallet (2) ( The mover (11) that constitutes the linear pulse motor is fixed to the lower surface of 2a).

In FIG. 3, the stator (10) is composed of two primary side electromagnets (1) which are arranged along the rail (6) at a small interval.
2), (13), permanent magnets (14), (15) fixed to the lower ends of the electromagnets (12), (13), and a yoke (16). Each electromagnet (12), (13) has a coil wire wound around a U-shaped iron core (12a), (13a) opening upward, and a concave character is formed at the upper end of each iron core (12a), (13a). Magnetic teeth (17), (1
8), (19), and (20) are formed. When the magnetic wire (17) side is right-handed, the coil wire is left-handed on the magnetic tooth (18) side, and the magnetic tooth (19) side is left-handed, and the magnetic tooth (20)
The side is wound so that it is right-handed. Further, the right permanent magnet (14) is arranged so that the side adjacent to the iron core (12a) has the N pole, and the left permanent magnet (15) has the south pole adjacent to the iron core (13a). Has been done.

The mover (11) is composed of a motor rack having a large number of magnetic teeth (22) on its lower surface, and is formed of an iron-based magnetic conductor. The length of the mover (11) in the direction along the rail (6) is
(0) is set to the sum of the side end length between the magnetic teeth (17) and (20) at both ends and the side end length of the work (W). The magnetic teeth (22) of the mover (11) are formed at a constant pitch, and the four magnetic teeth (17), (1
The positions of the magnetic teeth (17), (18), (19), and (20) are set so that each of 8), (19), and (20) is displaced by a quarter pitch. For example, in FIG. 3, when the magnetic teeth (17) face the magnetic teeth (22) on the mover (11) side,
Each of the magnetic teeth (19), (20), (18) is set to deviate from the opposing magnetic teeth (22) by a quarter pitch. In this state, the electromagnet (12) is excited to generate the magnetomotive force and electromagnetic force (12) of the permanent magnet (14) on the magnetic tooth (17) side.
When the magnetomotive forces of (1) and (3) are matched, only the magnetic teeth (17) and the magnetic teeth (22) attract each other, and the magnetomotive force of the permanent magnet (14) and the magnetomotive force of the electromagnet (12) on the magnetic tooth (18) side. Repulsing each other, no force acts between the magnetic teeth (18) and the magnetic teeth (22). Further, only the magnetomotive force of the permanent magnet (15) acts on the magnetic teeth (19) and (20) side, and both (19) and (20) are even with respect to the magnetic teeth (22) of the mover (11). Apply suction force to. Therefore,
In this state, the pallet (2) can be fixed immovably.

When moving the pallet (2) in the direction of the arrow from the above fixed state, the excitation of the electromagnet (12) is cut off and the magnetic teeth (20)
The electromagnet (13) is excited so that the magnetomotive force of the permanent magnet (15) and the electromagnetic force match each other. Then, the neighboring magnetic teeth (22) are attracted by the magnetic teeth (20), and both magnetic teeth (20), (22)
Will stop in the state of facing. After that, by alternately exciting the electromagnets (14) and (15) so that the attractive force acts on the magnetic teeth (18), the magnetic teeth (19), the magnetic teeth (17), and the magnetic teeth (20) in this order, The pallet (2) can be continuously fed and driven by a quarter pitch of the magnetic teeth (22). By changing the excitation procedure, it is possible to drive in the opposite direction. In the fixed state, any one of the magnetic teeth (17), (18), (19), (20) faces the magnetic teeth (22) on the mover (11) side.

As described above, the pallet (2) sent from the previous process by the stator (10) moves while rolling to the next work station (S) due to the motion inertia. The pallet sensor (23) is provided for each station (S) in order to stop the pallet (2) that has moved at a predetermined position.
Are mounted on rails (6). Further, a position sensor (24) for detecting the absolute position of the pallet (2) is provided between the inner surface on one side of the frame (5) and the bottom surface of the pallet (2). Both sensors (23) and (24) output a detection signal to the controller (25). Pallet sensor (23)
When the controller detects the passage of the tip of the pallet (2), the controller (25) issues a braking operation command to the stator (10) to forcibly stop the pallet (2). At this time, if the mover (11) is at a position displaced from the preset origin position with respect to the stator (10), the position sensor (24) reads the amount of deviation and the mover (11) Control the stator (1) to stop at the origin. The position sensor (24) is composed of, for example, a linear motion type resolver or a rotary encoder, and also detects the moving position of the pallet (2) when the component (P) is assembled.

In FIG. 1, the assembly robot (4) has a Y-axis (26).
And a degree of freedom in the Z-axis (27) direction, and in some cases, a swing operation around the Z-axis (27) can be performed, and the component (P) is driven based on an operation command from the controller (25). ) Is attached to the work (W). The operation in the X-axis direction is performed on the pallet (2) side.

According to the work transfer device configured as described above, braking of the pallet (2) at each work station (S), localization fixing, fixing release, and feed driving to the next process are performed.
Since it can be performed by controlling the electromagnetic force of the stator (10) provided on the transfer path (1), a series of transfer operations can be efficiently performed without wasting time. Further, at the time of assembling the parts (P), the assembly robot (4) and the pallet (2) are reciprocally driven in the X-axis direction at the same time to position the assembling parts. Therefore, the time required for assembly can be reduced and the actual work speed at each station (S) can be improved. Moreover, it is possible to reduce the degree of freedom of operation of the assembly robot (4), simplify the structure, and reduce the facility cost of the entire line.

(Modification) Contrary to the above embodiment, the stator (10) is formed of a motor rack, and the mover (11) has electromagnets (12), (1
It can be modified to have 3). In this case, the motor rack may be provided over the entire length of the transport path (1).

Further, although the permanent magnet type linear step motor is applied in the embodiment, a variable reluctance type linear step motor or another linear motor can be applied, and therefore the type of the linear motor is not limited. .

As the moving means of the pallet (2), other than the rollers, linear guide-shaped steel balls may be used as rolling elements, and the rails (6) need not be a pair of two. In some cases, each station (S)
It is also possible to use a rail (6) or a guide head finished with high precision only in the portion corresponding to.

The work transfer device of the present invention may be applied to a production line other than an assembly line, and may be applied to a processing line for processing or finely processing the surface of a work (W). .

It should be noted that the pallet (2) can be moved by tilting the rail (6) by gravity, and when the adjoining space between the work stations (S) is large, the pallet (2) is fed to the midway part thereof. It may be equipped with a booster. Of course, the pallet (2) may be self-propelled.

(Effects of the Invention) As described above, in the work transfer device according to claims (1) to (3), the stator (10) and the mover (11) constituting the linear motor are connected to the transfer path (1). Each work station (S) is provided on the pallet (2) by applying an electromagnetic force between the stator (10) and the mover (11).
Since the pallet (2) can be stereotactically fixed in this manner, the operations from positioning to stereotactic fixation and release of fixation can be instantaneously performed by electromagnetic force, resulting in dead time for a series of carrying operations. It can be done efficiently without any effort.

Further, during actual work, the pallet (2) can be reciprocally driven via the mover (11) and the positioning in the driving direction can be performed on the pallet (2) side. It is possible to reduce the degree of freedom of movement required by the actual work device. As a result, the actual work device can perform the actual work with a simpler operation, and the actual work speed and the work efficiency can be improved accordingly. further,
Since the structure of the actual work device can be simplified by reducing the freedom of movement, the manufacturing cost can be reduced and the facility cost of the entire production line can be reduced.

Further, since the movable element (11) can be stopped without being displaced to the origin by detecting the absolute position of the pallet (2), there is an advantage that the pallet (2) can be fixed at a fixed position with high accuracy at all times.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a vertical sectional side view of a work transfer device, Fig. 2 is a plan view of a part of an assembly line, and Fig. 3 is a sectional view taken along line AA in Fig. 2. It is a figure. (1) …… Conveying path, (2) …… Pallet, (6) …… Rail, (7), (8) …… Roller, (10) …… Stator,
(11) …… Mover, (S) …… Work station,
(W) …… Work.

Claims (3)

[Claims] 1. A stationary transfer path (1), a pallet (2) movably guided and supported by the transfer path (1) to transfer a work (W), and along the transfer path (1). A plurality of work stations (S) arranged in parallel, a stator (10) that is provided for each work station (S) in the transport path (1) and constitutes a linear motor, and the pallet (2). A mover (11) provided corresponding to the stator (10) and constituting a linear motor, and a mover (1) provided for each of the work stations (S) in the transport path (1), A pallet sensor (23) for detecting the passage of the tip portion, and a transport path (1) corresponding to each of the work stations (S)
And a pallet (2) are provided between the pallet (2) and a position sensor (24) for detecting the absolute position of the pallet (2), and the output of the pallet sensor (23) is received to forcibly stop the pallet (2). To generate a braking operation command signal to the stator (10) and receive the output of the position sensor (24) to stop the mover (11) of the pallet (2) at the origin. ), A controller (25) for controlling the work, and a work transfer device. 2. The linear motor comprises a linear pulse motor, and the electromagnets (12) and (13) on the primary side of the linear motor are connected to the stator (1
The work transfer device according to claim (1), wherein the work path (1) is provided on the transfer path (1), and the motor rack on the secondary side is provided on the pallet (2) as the mover (11). 3. The work transfer device according to claim 1, wherein the position sensor (24) is a linear motion type resolver.