JP2011062032A - Linear servo actuator mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear servo actuator mechanism which is reduced in weight, is not limited in arrangement when adopted in a linear servo gun for spot welding, and allows simplification of a configuration that supports the linear servo actuator mechanism. <P>SOLUTION: A movable electrode 12 of a spot welding machine 1 is caused to move in strokes. Four fixing members 8 arranged in parallel with each other are provided with stators 15 having coils 17. A movable member 10 has openings 10h in which the fixing members 8 are inserted, and movers 9 having permanent magnets 14 are arranged in the openings 10h thereof. The movable electrode 12 is disposed at the front end of the movable shaft 11 of the movable member 10. The coils 17 of the fixing members 8 are formed such that the coil of one fixing member 8a extends over its entire length, while coils of the other three fixing members 8b to 8d extend over part of their lengths so that a greater thrust is created when the movable electrode 12 comes in abutment with a workpiece W and then presses the workpiece W. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear servo actuator mechanism that is employed, for example, on the movable electrode side of a stationary spot welding apparatus.

Conventionally, as a linear actuator that combines a magnet such as a coil or solenoid and a magnet, a plurality of electromagnets are arranged in parallel to generate a magnetic force equivalent to that of a single electromagnet, and a conventional single electromagnet is used. A technique is known for reducing the size and width of an apparatus by reducing the width and length while obtaining the same driving force. (For example, refer to Patent Document 1.)
In addition, as a linear motor that can easily extract thrust and achieve high thrust and high acceleration performance, an outer yoke unit in which a single pole magnet is fixed in an annular shape in the hollow part of the outer yoke, and a winding around the outer periphery of the inner yoke By arranging in parallel a plurality of linear units composed of an inner yoke unit composed of a plurality of sets of coils and a spacer that connects the outer yoke units with an axially specific portion so that the coils and magnets face each other, A technique is also disclosed in which high thrust can be obtained while reducing the weight on the outer yoke unit side. (For example, see Patent Document 2.)

JP-A-62-233581 JP 2004-282833 A

However, in the case of Patent Document 1, although the electromagnets are divided in parallel, the total amount of coils and the like does not change in order to obtain a magnetic force equivalent to that of a single electromagnet, and thus the weight of the electromagnet cannot be reduced. It was.
In the case of Patent Document 2, the weight of the outer yoke unit is reduced because the weight of the inner yoke unit having many windings such as coils is heavier than that of the outer yoke unit to which the magnet is fixed. However, the overall weight of the linear motor was not reduced much.

  For this reason, when such a conventional technology is adopted for a linear servo gun for spot welding, the load of the linear motor is large, the configuration for supporting this is enlarged, the cost is increased, and the linear servo for spot welding is increased. There was a problem that the placement of guns was restricted.

  Therefore, the present invention reduces the weight of the linear servo actuator mechanism, and in particular, the arrangement is not limited even when it is used in a linear servo gun for spot welding, and the configuration for supporting this is simplified. The purpose is to.

  In order to achieve the above object, the present invention comprises a movable member in which a plurality of apertures are formed, and a plurality of fixed members that are inserted through the apertures of the movable member. A linear element in which a movable element provided with a permanent magnet is disposed and a fixed element provided with a coil portion is provided on each of the fixed members, so that a thrust is applied to the movable member and the movable member can be moved by a predetermined stroke. In the servo actuator mechanism, the stator coil portion at the predetermined location is partially provided on the fixed member at the predetermined location so that the necessary thrust force can be formed during the stroke of the movable member.

That is, a constant thrust is not always required while the movable member is moving for a predetermined stroke, but a strong thrust is required at a certain location, but a strong thrust is required when a relatively weak thrust is sufficient at a certain location. Coil parts are provided on all the fixing members where necessary, and the coil part is provided at a part where sufficient thrust is sufficient, so that the total amount of the coil parts can be reduced. Can be reduced.
For this reason, the weight of the entire actuator mechanism can be reduced.

  In the spot welding apparatus, when the movable electrode is moved up and down, a relatively weak thrust that only needs to be moved is sufficient until the workpiece comes into contact with the electrode, and it is necessary to apply a predetermined pressure after contacting the workpiece. A strong thrust is required. For this reason, it is preferable to apply such a linear servo actuator mechanism to the movable electrode side of the spot welding apparatus.

During the stroke of the movable member, the coil portion is partially formed so that the necessary thrust is formed at that time, thereby reducing the weight of the mechanism itself and reducing the cost.
It is preferable to apply such an actuator mechanism to the movable electrode side of the spot welding apparatus.

It is a front view of the spot welding apparatus by which the linear servo actuator mechanism which concerns on this invention is employ | adopted. It is a front view of the linear servo actuator mechanism which concerns on this invention. It is A view of FIG. It is the enlarged view which shows the internal structure of the B section of FIG. 2, (a) is the figure seen from the front direction, (b) is sectional drawing. It is explanatory drawing which shows typically the linear servo actuator mechanism which concerns on this invention. It is explanatory drawing which shows typically the other Example of the linear servo actuator mechanism which concerns on this invention.

  The linear servo actuator mechanism according to the present invention is reduced in weight, and in particular, the arrangement is not limited even when it is used in a linear servo gun for spot welding, and the configuration for supporting this can be simplified. In the present embodiment, the present invention is applied to a spot welding apparatus in which a coil portion is partially arranged so that a necessary thrust is formed during the stroke of the movable member. ing.

  That is, as shown in FIG. 1, a stationary C-type spot welder 1 to which a linear servo actuator mechanism according to the present invention is applied is provided on a base 3 supported by a column 2 and on the column 2. A welding transformer 4 is provided, and an elevating mechanism 6 having a plurality of actuators 5 employing the linear servo actuator mechanism is disposed on the base 3.

  As shown in FIGS. 2 and 3, the elevating mechanism 6 is arranged in parallel at equal intervals between the substrate plates 7a and 7b arranged in the left-right direction in FIG. 2 and the substrate plates 7a and 7b. And four fixed members 8 on which a stator 15 to be described later is disposed, a movable member 10 having respective openings 10h through which the four fixed members 8 can be inserted, and the four openings 10h. A movable shaft 11 that is fixed to one end of the movable member 10 in parallel with the axial direction of the fixed body 8 and protrudes to the outside on one side, and a movable electrode 12 that is attached to the tip of the movable shaft 11. The one side substrate plate 7a is formed with an insertion hole through which the movable shaft 11 can be inserted.

  As shown in FIG. 4, a cylindrical member 13 is attached to the inner surface of each opening 10 h of the movable member 10, and an annular permanent magnet 14 is provided on the inner surface of the cylindrical member 13. It has been. And this permanent magnet 14 is comprised as several sequences spaced apart in the width direction of the opening 10h, and the needle | mover 9 is comprised by the cylindrical member 13 and the permanent magnet 14. FIG.

  In the fixing member 8, a portion in which a stator 15 described below is disposed and a fixing member 8 in which the stator 15 is partially disposed are mixed at all locations in the length direction. The structure of the fixing member 8 where the stator 15 is disposed will be described. As shown in FIG. 4, a plurality of rows of coil portions 17 wound around the pipe member 16 and the coil portions 17 are arranged. A stator 15 is constituted by a core portion 18 disposed between and a cylindrical member 19 made of resin that covers the outer periphery of the coil portion 17 and the core portion 18.

As shown in FIG. 5, the stator 15 is formed on the entire length of one fixing member 8 a (blacked portion), and the other three fixing members 8 b to 8 d. Thus, the stator 15 is formed only on the tip side.
In addition, when such an elevating mechanism 6 is set in the spot welder 1 of FIG. 1, all the fixing members 8 are set with the side on which the stator 15 is formed facing downward.

  On the other hand, in the spot welding machine 1 shown in FIG. 1, the fixed electrode 21 disposed to face the movable electrode 10 is disposed at the tip of a C-type fixed arm 22 connected to the lower surface of the base 3. The fixed electrode 21 is electrically connected to the welding transformer 4 via the C-type fixed arm 22. The movable electrode 12 is also electrically connected to the welding transformer 4 via the movable shaft 11.

In the above configuration, when spot welding is performed, the movable electrode 12 is raised to the position of the ascending end, that is, the position where the movable member 10 contacts the upper substrate plate 7b, and is made to stand by as the original position. 21. Set work W on 21.

  Next, the elevating mechanism 6 is controlled to lower the movable member 10. At this time, until the movable member 10 moves from the rising end to the vicinity of the intermediate position, as shown in FIG. The driving is controlled by the thrust of only the child 15, and from the vicinity of the intermediate position, the driving is controlled by the thrust of the stator 15 of the four fixing members 8a to 8d. For this reason, the necessary welding pressure is finally ensured by the strong thrust, and the spot welding is completed if energized in this state.

  When the spot welding is completed, the stator 15 of the four fixing members 8a to 8d is controlled to start rising, but from the vicinity of the intermediate position, the fixing member 8a that is sufficient to raise the movable member 10 is fixed. It is driven by the child 15, moved to the ascending end, and waits at the original position.

  If the arrangement of the coil portion 17 of the stator 15 is omitted in the section that does not require much thrust by the above procedure, the entire lifting mechanism 6 can be reduced in weight, and the structure of the support column 50 The degree of freedom in arranging the welding machine 1 can be increased.

  In the above embodiment, all the actuators 5 of the elevating mechanism 6 are controlled at the same time. However, at the initial stage when the movable member 10 moves downward from the original position, only one actuator 5 is used. It is also possible to control all the actuators 5 in the vicinity of the lower end and to control only one actuator 5 again after the work is completed.

  In addition, this invention is not limited to the above embodiments. What has substantially the same configuration as the matters described in the claims of the present invention and exhibits the same operational effects belongs to the technical scope of the present invention. For example, although the said Example showed the example which uses the four fixing members 8a-8d, as shown in FIG. 6, it is also possible to use two fixing members 8a and 8b. In this case, it is necessary to increase the length of the movable member 10 in order to obtain the same thrust as when using the stator 15 of the four fixed members 8a to 8d. For this reason, the lengths of the fixing members 8a and 8b are inevitably increased.

  In a linear servo actuator mechanism using an electromagnet such as a coil, it is possible to reduce the weight by eliminating waste at the location where the coil is installed.

DESCRIPTION OF SYMBOLS 1 ... Stationary type C spot welder, 5 ... Actuator, 6 ... Elevating mechanism, 8 ... Fixed member, 9 ... Movable member, 10 ... Movable member, 10h ... Opening, 14 ... Permanent magnet, 15 ... Stator, 17 ... coil part.

Claims (2)

A movable member having a plurality of apertures and a plurality of fixed members that pass through the apertures of the movable member are provided, and a movable element having a permanent magnet is disposed on the inner surface of each aperture of the movable member. In addition, a linear servo actuator mechanism that provides a thrust to the movable member by providing a stator having a coil portion on each of the fixed members, thereby enabling the movable member to move by a predetermined stroke, wherein the predetermined portion The linear servo actuator mechanism is characterized in that a coil portion of the stator is partially provided on a fixed member at a predetermined location so as to be sufficient to form a thrust required at that time during a stroke of the movable member. The linear servo actuator mechanism according to claim 1, wherein the linear servo actuator mechanism is applied to a movable electrode side of a spot welding apparatus.