JPH01271133A - Workpiece conveyance device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a workpiece conveyance device applied to an assembly line, for example, in which the workpiece conveyance device has a positioning function of 117.
The aim is to improve transport and actual work efficiency.

(Prior art) Conventional conveyance device of this type and 1. Then, the pallet loaded with the workpiece is transferred by a conveyor, and after the pallet is forcibly stopped at each station, the pallet is positioned and fixed by operating a positioning member such as a bin, and the parts are inserted into the workpiece using an inserter or assembly robot. Assembling is known (documents unknown) (Problem to be solved by the invention) As described above, in the conventional device, the fixed position of the pallet at each work station is achieved by mechanical engagement of positioning members. Is going. Therefore, actual work such as assembling parts cannot be performed until after the fixed position of the pallet is completed, and furthermore, after the actual work is completed, the fixed position of the pallet must be released before proceeding to the next process. This means that the pallet cannot be moved. In other words, it is unavoidable that wasted time is required to fix and release the fixed position of the pallet at each station, and as the actual work speed and transfer speed between work stations improve, the wasted time becomes a problem. It has become to.

Furthermore, since parts are assembled while the pallet is fixed in position, the inserter or assembly robot side performs all spatial positioning of the parts to be assembled. Therefore, actual work equipment such as assembly robots must have more degrees of freedom of movement, and the more degrees of freedom of movement, the more time it takes to perform the work, which makes it difficult to increase the actual work speed. But there was a problem. Furthermore, in order to support high-mix, low-volume production,
Assembly robots with a high degree of freedom of movement will be installed at all work stations, increasing the flexibility of work at each station, but in this case, the overall cost of the production line will inevitably increase, and equipment costs will increase. I was dissatisfied with the bulk.

The present invention solves the above problem, and by fixing the pallet in a fixed position at a work station using electromagnetic force, it eliminates wasted time required for fixing the pallet in the fixed position and releasing the fixed position, and improves conveyance efficiency. With the goal.

Another object of the present invention is to enable the pallet to be reciprocated within a certain range at each work station, and to position the pallet itself so that it can be displaced relative to the actual working equipment, thereby allowing freedom of movement of the actual working equipment. The aim is to improve work speed by reducing energy consumption and reduce equipment costs at the same time.

(Means for Solving the Problems) Therefore, in the present invention, a linear motor is used to fix the fixed position of a pallet at a work station and reciprocate within a certain range, thereby improving conveyance efficiency and increasing actual working speed. Achieve improvements, etc.

Specifically, as shown in FIG. 1, in the invention of claim (1), a stator constituting a linear motor corresponds to each work station (S) arranged along the conveyance path (1). (
10) is provided on the conveyance path (1), and the mover of the linear motor (
11) is provided on the pallet (2) side. The pallet (2) is connected to the conveyance path (1) by, for example, rollers (7), (
8), so that the air gap between the mover (11) and the stator (10) is maintained at a constant value. In this case, in the invention of claim ('2J), in order to accurately fix the localization, the stator (10) is used as a linear motor with the primary side electromagnets (12) and (13), and the movable element (11) is It is preferable to use a linear pulse motor configured with a motor rack on the next side.

Furthermore, in the invention of claim (3), in order to compensate for the displacement of the mover (11) with respect to the stator (10), the pallet (2
) is provided between the conveyance path (1) for each work station (S) and each pallet (2). This position sensor (2
As for 4), a linear motion resolver is used as in claim (4).

(Function) As a result, according to the invention of claim (1), the conveyance path (1
) and the mover (11) provided on the pallet (2), electromagnetic force is applied to fix the orientation of the pallet (2) at each work station (S). Since this is carried out, positioning, fixing, and fixing release can be performed instantaneously, and a series of conveyance operations can be performed efficiently without wasting time. especially,
If a linear pulse motor is used as in claim (2), the above-mentioned localization can be fixed with higher accuracy. Furthermore, by controlling the magnetic field state of either or both of the stator (10) and the movable element (11), the movable element (11) can be controlled.
]), the pallet (2) can be reciprocated via the pallet (2), so by displacing the pallet (2) with respect to the actual working device, the degree of freedom of movement of the actual working device corresponding to this displacement direction can be reduced. Accordingly, the actual work speed can be increased by that much, and work efficiency can be improved. At the same time, the structure of the actual work equipment can be simplified and the cost required for the entire line can be reduced.

Furthermore, in the inventions of claims (3) and (4), when the pallet (2) stops, the movable element (11) moves toward the stator (10).
If the movable element (11) is at a position deviated from a preset origin position, the position sensor (24) detects the amount of deviation and controls the stator (10) so that the movable element (11) stops at the origin. is possible.

(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 conveyance path (]) arranged in an endless loop, a large number of pallets (2) movably guided and supported by this conveyance path (1), and the conveyance path (
1) Consists of a large number of work stations (S) arranged at predetermined intervals along the
The pallet (2) on which the parts (P) are loaded and fixed moves along the conveyance path (1), and the parts (P) are loaded and fixed at each work station (S).
It is designed to undergo assembly and processing. Each station (S) has a parts feeder (
3), an assembly robot (4), or actual work devices such as a workpiece (W) mounting device are provided.

The conveyance path (1) consists of a frame (5) that is fixed in place and a pair of rails (6), (6) provided on both sides of the upper end of this frame (5).
(6) guides the movement of the pallet (2). The pallet (2) consists of a base plate-like main body (2a) and this main body (2a).
four rollers (7) rotatably supported on both sides of the main body (2a), four rollers (8) rotatably supported on the lower surface of the main body (2a), and a work holding mechanism (not shown). It consists of Of both rollers (7), (8), the former roller (7) moves on the upper surface of the rail (6), (6), and the latter roller (8) moves on the upper surface of the rail (6).

(6), move the pallet (2) along the rails (6), (6), and move both rollers (6) at the same time.
The cooperative action of 7) and (8) allows the traveling posture of the pallet (2) to be precisely regulated.

The pallet (2) is fixed in position at each station (S),
Alternatively, in order to move relative to the assembly robot (4), a drive means applying the principle of a linear motor is used on the transport path (4).
1) and each pallet (2). 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
2a) On the bottom surface of the movable element (
11) is fixed.

In FIG. 3, the stator (10) consists of two primary electromagnets (12) arranged along the rail (6) with a booth spaced apart.
), (13) and each electromagnet (12), (13)
It consists of permanent magnets (14), (15) fixed to the lower end of the yoke and a yoke (16). Each electromagnet (1, 2), (1
3) is a U-shaped iron core (12a) that opens upward;
(13a) The coil wire is wound around the device 7, each iron core (12a),
(17), (1
8), (19).

(20) is formed. The coil wire has magnetic teeth (]7
) side is right-handed, the magnetic tooth (18) side is left-handed,
Furthermore, the wires are wound so that the magnetic tooth (one) side is left-handed, and the magnetic tooth (20) side is wound right-handed.

In addition, the permanent magnet (14) on the right side of the figure has an iron core (1,
2a ) is the N pole, and the permanent magnet on the left (
15) is arranged so that the side adjacent to the iron core (13a) is the south pole.

The mover (11) consists of a motor rack having a large number of magnetic teeth (22) on its lower surface, and is made of an iron-based magnetic conductor. The length of the mover (Xi) in the direction along the rail (6) is determined by the magnetic teeth (co-7) at both ends of the stator (]0), the length of the side edge of the earthen floor (20), and the length of the workpiece (W). The length is set to the sum of the side end length. The magnetic teeth (22) of the mover (11) are formed with a constant pitch, and based on this, the four magnetic teeth (17), (18), (19), (20) of the stator (10) are ) so that each magnetic tooth (17) is displaced by a quarter pitch.
, (18), (19), and (20) are fixed positions. For example, in FIG. 3, when the magnetic tooth (17) directly faces the magnetic tooth (22) on the mover (11) side, the magnetic tooth (
19), (20), and (18) are each set to be offset by a quarter pitch with respect to the opposing magnetic tooth (22). In this state, when the electromagnet (12) is excited to match the magnetomotive force of the permanent magnet (14) and the magnetomotive force of the electromagnet (12) on the magnetic tooth (17) side, the magnetic tooth (17)
) and the magnetic tooth (22) attract each other, and on the magnetic tooth (18) side, the magnetomotive force of the permanent magnet (14) and the magnetomotive force of the electromagnet (12) repel each other, and the magnetic tooth (18) and the magnetic tooth There is no force acting between (22) and (22). In addition, magnetic teeth (19), (
On the 20) side, only the magnetomotive force of the permanent magnet (15) acts,
Both (19) and (20) are the magnetic teeth (
22) Apply suction force evenly to the objects. 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 electromagnet (12) is de-energized and the magnetic teeth (20
), the electromagnet (13) is excited so that the magnetomotive force of the permanent magnet (15) matches the electromagnetic force. Then, magnetic teeth (20
) attracts the neighboring magnetic tooth (22), and both magnetic teeth (2
0) and (22) are directly facing each other. Hereafter, magnetic teeth (18), magnetic teeth (19), magnetic teeth (17), magnetic teeth (2o)
Electromagnets (14) and (15) are arranged so that the attractive force acts in the order of
) by alternately exciting the pallet (2), the pallet (2) can be driven to be continuously fed by one quarter pitch of the magnetic teeth (22). By changing the excitation procedure, it is also possible to drive in the opposite direction. In addition,
In the fixed state, the magnetic teeth (17), (18), (19
), (20) directly opposes the magnetic tooth (22) on the movable element (11) side.

As described above, the pallet (2) sent out from the previous process by the stator (10) rolls and moves to the next work station (S) due to kinetic inertia. In order to stop this moving pallet (2) at a predetermined position, a pallet sensor (23) is installed at each station (S).
) is attached to the rail (6). Also, between the negative inner surface of the frame (3) and the bottom of the pallet (2),
A position sensor (24) detects the absolute position of the pallet (2).
) is provided. If this position sensor (24) is composed of a linear-acting resolver, the pallet sensor (23) is used as a sensor for returning to the origin, since the absolute value can only be obtained within the park and there is no big difference from the increment. It will be done.

Both sensors (23) and (24) are connected to the controller (25
) to output a detection signal. When the pallet sensor (23) detects passage of the leading end of the pallet (2), a braking operation command is issued from the controller (25) to the stator (1o), and the pallet (2) is forcibly stopped. At this time, if the movable element (11) is at a position shifted from the preset origin position with respect to the stator (10), the position sensor (24) reads the amount of deviation, and the movable element (11) The stator (10) is controlled to stop at the origin. Position sensor (24
), for example, consists of the above-mentioned linear-acting resolver or rotary encoder', both of which require a sensor for returning to the origin, and a pallet (2) when assembling part CP).
) is also detected.

In FIG. 1, the assembly robot (4) is located on the Y axis (26
) and the Z-axis (27), and is configured to be able to rotate around the Z-axis (27) in some cases. Assemble P) to the workpiece (W). Movement in the X-axis direction is performed on the pallet (2) side.

According to the workpiece conveyance device configured as above, the conveyance path (1) is provided with the braking stop, localization fixing, fixing release, and feeding drive of the pallet (2) at each work station (S) to the next process. Since this can be performed by controlling the electromagnetic force of the stator (10), a series of conveyance operations can be performed efficiently without wasting time. In addition, parts (P) are sometimes assembled on the pallet (P) at the same time as the assembly robot (4).
By reciprocating the assembly robot (2) in the X-axis direction and positioning the assembly robot (4), the amount of movement of the assembly robot (4) can be reduced, reducing the time required for assembly. The actual work speed in S) can be improved. Furthermore, it is possible to reduce the degree of freedom of movement of the assembly robot (4), simplify the structure, and reduce equipment costs for the entire line.

(Modification) Contrary to the above embodiment, the stator (10) is formed by a motor rack, and the movable element (11) is the primary electromagnet (12),
(13) can also be modified.

In this case, the motor rack may be provided over the entire length of the conveyance path (1).

In addition, although the example uses a permanent magnet type linear step motor, a variable reluctance type linear step motor or other linear motor can also be applied, so the type of linear motor is not limited. .

The means for moving the pallet (2) may be one that uses linear guide-like steel balls as rolling elements in addition to rollers, and the rails (6) do not need to be a pair of two. In some cases, only the parts corresponding to each station (S) are finished with high precision rails (6)
It is also possible to use a guide head.

The workpiece conveyance device of the present invention can be applied to production lines other than assembly lines, and may be applied to processing lines that perform surface treatment or micromachining of workpieces (W), for example. .

The pallet (2) can also be moved by gravity by tilting the rail (0), and if the distance between adjacent work stations (S) is large, the pallet (2) can be fed halfway between the work stations (S). It may also be equipped with a booster.

Of course, the pallet (2) may be self-propelled.

(Effects of the Invention) As explained above, in the workpiece conveyance devices of claims (1) and (2), the stator (]0 that constitutes the linear motor)
and a mover (1) are provided on the conveyance path (1) and the pallet (2), respectively, and by applying electromagnetic force between the stator (10) and the mover (11), each work station is Since the pallet (2) can be fixed in position at (S), the operations from positioning to fixing and releasing the fixation can be performed instantaneously using electromagnetic force, eliminating a series of wasted conveyance operations. This can be done efficiently without wasting time.

Also, during actual work, the pallet (
2) can be reciprocated and the positioning in the drive direction can be performed on the pallet (2) side, which reduces the degree of freedom of movement required by actual work equipment such as the assembly robot (4), for example. It becomes possible. As a result, the actual work device can perform actual work with simpler operations, and the actual work speed can be increased accordingly, thereby improving work efficiency. Furthermore, since the structure of the actual working device can be simplified by reducing the degree of freedom of movement, the manufacturing cost can be reduced, and the equipment cost for the entire production line can be reduced.

Furthermore, according to the conveying device of claims (3) and (4),
The absolute position of the pallet (2) is detected and the mover (11)
Since the pallet (2) can be stopped at the origin without deviation, it has the advantage that the localization of the pallet (2) can always be fixed with high accuracy.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal side view of the workpiece conveyance device, FIG. 2 is a plan view of a part of the assembly line, and FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. It is a diagram. (1)...Conveyance path, (2)...Pallet, (6)...
...Rail, (7), (8)...Roller, (1o
)... Stator, (1])... Mover, (S)... Work station, (W)... Work. 1”・-′, Patent applicant: Daigin Kogyo Co., Ltd.;
,, 1.1゜1',j, - Agent Patent Attorney Former H] Hiroshi %
=('71'-:IL)

Claims (4)

[Claims] (1) It has a fixed conveyance path (1) and a pallet (2) that is movably guided and supported by this conveyance path (1) to transfer a workpiece (W), A stator (S) forming the linear motor corresponds to each work station (S) arranged along the line.
10) is provided on the transport path (1), and the pallet (2) is provided with a mover (11) constituting a linear motor corresponding to the stator (10). (2) The linear motor consists of a linear pulse motor, and the electromagnets (12) and (13) on the primary side are connected to the stator (10).
) is provided on the conveyance path (1), and the motor rack on the secondary side is provided as a mover (11) on the pallet (2).
1) The workpiece conveyance device described above. (3) Conveyance path (1) corresponding to each work station (S)
) and each pallet (2), a position sensor (24) for detecting the absolute position of the pallet (2) is provided. (4) The workpiece conveyance device according to claim 1, (2) or (3), wherein the position sensor (24) comprises a linear motion resolver.