JP2013107157A - Chuck device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck device capable of surely holding a hollow cylindrical workpiece.SOLUTION: The chuck device 1 includes a chuck body 5 and three chuck members 15 disposed on a tip side of the chuck body 5 to hold a hollow cylindrical metallic workpiece 3, which holds the workpiece 3 by moving the chuck members 15 from the radial direction outside to the inside toward a central axis of the workpiece 3 disposed in a prescribed fixed position on the tip side of the chuck body 15. Apical surfaces 23 of all the chuck members 15 contacting the workpiece 3 are inclined in the same direction as the moving direction to the radial direction inside, when the workpiece 3 is viewed from an axial direction.

Description

  The present invention relates to a chuck device capable of grasping and transporting a hollow cylindrical metal member or fixing it to a lathe or the like. In particular, it is suitable for transporting a member having a detection element inside a hollow cylindrical metal member, such as an oxygen sensor for automobile use.

2. Description of the Related Art Conventionally, a workpiece holder device (chuck device) used in a machine tool or the like has been proposed as a device that holds and holds a cylindrical member (workpiece) (see Patent Document 1).
This chuck device is provided with three rectangular parallelepiped chuck claws at an equal interval of 120 ° on the tip surface of a cylindrical chuck body, and the chuck claws can be moved in the radial direction with respect to the central axis of the chuck body. It is attached to.

  When holding a workpiece with this chuck device, place the workpiece coaxially along the central axis of the chuck body on the tip side of the chuck body, and center the three chuck claws from the outside in the radial direction of the workpiece. The outer periphery of the workpiece was pressed and held by moving radially inward toward the shaft.

Japanese Utility Model Publication No. 61-1306

  However, in the case of the above-described prior art, the surface of the chuck claw that contacts the workpiece has a flat plate shape perpendicular to the moving direction of the chuck claw (or a shape in which irregularities are formed on the surface of the vertical flat plate). Therefore, when the workpiece is sandwiched by the chuck claws from three directions, a problem may occur.

  Specifically, for example, when there is a tolerance shift (for example, a dimensional shift in the radial direction) in the cylindrical workpiece, or an axis shift of the chuck device (that is, a shift in the moving direction of each chuck claw to the central axis). In such cases, there are cases where the workpiece is held by two chuck claws (so-called two-point holding), and when such two-point holding occurs especially during workpiece transfer, the force is evenly transmitted to the workpiece. In some cases, the workpiece fell or the workpiece transfer device stopped.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a chuck device that can reliably hold a hollow cylindrical workpiece.

  (1) The present invention includes, as a first aspect, a chuck body and three chuck members that are disposed on the tip side of the chuck body and hold a hollow cylindrical metal workpiece, In the chuck device that holds the work by moving the chuck member from the radially outer side to the center axis of the work with respect to the work placed on the work piece, all the chuck members are made to contact the work. The contacting end surfaces are inclined in the same direction with respect to the radially inward moving direction when the workpiece is viewed from the axial direction.

  In the first aspect, the tip surfaces of the chuck members that are in contact with the workpiece are not perpendicular to the moving direction of the chuck member as in the prior art when the workpiece is viewed from the axial direction. It is inclined in the same direction with respect to the moving direction.

  Here, “inclined” means being inclined obliquely with respect to the moving direction, and not being parallel or perpendicular to the moving direction. Further, “inclined in the same direction” means that, as shown in FIG. 3, for example, the tip surface of the chuck member is radially on the right side (or on the left side) with respect to the moving direction inward in the radial direction. It means that it protrudes inward and is inclined.

  Therefore, when holding the workpiece, if the chuck member is brought close to the workpiece, the workpiece is pressed against the tip surface of the chuck member and moves, but the tip surface of the chuck member moves in the radial inward direction. Therefore, the workpiece tends to move obliquely so that the center axis of the workpiece deviates from the moving direction from a predetermined position where it is initially arranged. At this time, since the workpiece is pressed by the chuck member in the same manner from the three directions, as a result, the forces in the pressing direction are balanced and the workpiece is held at a predetermined position.

  Even if the chuck body or workpiece has a dimensional error, only the chuck member in two directions comes into contact with the workpiece first and the workpiece is likely to be held by the chuck member in two directions. Since the front end surface of the chuck member is inclined in the same direction, the workpiece is pressed by each chuck member so that the central axis is displaced from the moving direction, and the workpiece is moved in the direction in which the workpiece is pushed out between the two chuck members. Then, it is pressed by another chuck member. Therefore, work holding by the two-direction chuck member, so-called two-point holding is difficult to occur, and the workpiece is always held by the three-way chuck member.

For this reason, it is possible to effectively prevent the workpiece from being dropped or the workpiece conveyance device from being stopped due to such two-point holding particularly during the workpiece conveyance.
The chuck members are arranged in three directions at equal intervals (every 120 °) in the radial direction with respect to the center (axis center) at a predetermined fixing position of the workpiece (and hence the surface of the chuck body on the chuck member mounting side). ) Is more preferable from the viewpoint of preventing two-point holding.

(2) In the present invention, as a second aspect, when the workpiece is viewed from the axial direction, a triangle is formed by the tip surfaces of the three chuck members.
In the second aspect, since the workpiece is held such that the front end surface of each chuck member forms a triangle, the workpiece can always be reliably held.

Note that it is preferable that the triangle is an equilateral triangle because the center axis is difficult to shift when the workpiece is held.
(3) As a third aspect of the present invention, the workpiece has a connection location where the first member and the second member are connected, and the chuck member holds the workpiece at a location different from the connection location. It is characterized by doing.

  For example, in a connection location where different members are connected by welding or caulking, for example, a connection location by welding a protector of a sensor attached to an automobile exhaust pipe or the like to the metal shell, the connection location may be raised, The workpiece may not be held securely.

Therefore, in the third aspect, since the workpiece is held while avoiding such a connection portion, there is an advantage that the workpiece can be held reliably.
Here, “connection” includes joining by welding or the like and mechanical coupling by caulking or the like.

(4) The present invention, as a fourth aspect, is characterized in that the workpiece is a sensor having a protector.
In this 4th aspect, the workpiece | work is illustrated, The oxygen sensor and temperature sensor which have a protector are mentioned as this workpiece | work, The protector of a sensor is mentioned as a location hold | maintained.

It is a perspective view showing the state where the oxygen sensor was held in the chuck device of an embodiment. It is explanatory drawing which shows the side surface of a chuck | zipper apparatus. It is explanatory drawing which shows the front end side of a chuck | zipper apparatus. It is a perspective view which shows a chuck member. (A) is a top view (on the moving member side) of the chuck member, (b) is a side view of the chuck member, and (c) is a bottom view of the chuck member. It is explanatory drawing which shows the procedure which hold | maintains and conveys an oxygen sensor with a chuck | zipper apparatus. It is a front view which shows the state which opened the chuck member in the front end side of a chuck | zipper apparatus. It is a top view which shows the state which has arrange | positioned the protector in the space which the chuck member opened. It is a front view which shows the state which hold | maintained the protector with the chuck member in the front end side of a chuck | zipper apparatus. It is a top view which shows the state holding the protector with the chuck member.

Embodiments of the present invention will be described below with reference to the drawings.
In each embodiment described below, a chuck device that holds an oxygen sensor for obtaining an air-fuel ratio or the like in an automobile exhaust gas will be described as an example.
[Embodiment]
a) First, the configuration of the chuck device will be described.

  As shown in FIG. 1, the chuck device 1 of the present embodiment is a device that holds a work (here, an oxygen sensor) 3 on the tip side (lower side in FIG. 1), and is mainly made of a substantially cylindrical metal chuck. A main body 5, three chuck portions 7 arranged to be movable in the radial direction on the tip side of the chuck main body 5, and a moving mechanism 9 that moves the chuck portion 7 by air pressure are provided. Each configuration will be described below.

  The chuck body 5 is attached to a movable device 11 (see FIG. 2) such as an arm of a robot, for example, with the tip side facing the side where the workpiece 3 is disposed (lower side in FIG. 1). It can move freely in the vertical and horizontal directions.

  A guide recess 13 is formed on the front end side of the chuck body 5, and the guide recess 13 holds the chuck portion 7, and the chuck portion 7 is centered on the axis of the chuck body 5 (ie, the center axis). It is the groove | channel opened so that it could move to radial direction with respect to.

  Specifically, the guide recesses 13 are radially formed at equal intervals of 120 ° with respect to the central axis of the chuck body 5, and the first recesses 13 a that are radially cut into the front end surface 5 a of the chuck body 5 and It consists of the 2nd recessed part 13b cut into the circumferential direction both sides by the rear-end side (FIG. 1 upper side) of the 1st recessed part 13a.

  Further, as shown in FIG. 2, the chuck portion 7 includes a chuck member 15 made of, for example, polytetrafluoroethylene (PTFE) that directly contacts and holds the workpiece 3, and the chuck member 15 at its front end side (see FIG. 2). 2) and is made of a metal moving member 17 that moves in the radial direction integrally with the chuck member 15, and these are integrally fixed by a pair of screws 18 (see FIG. 1).

  Among these, the moving member 17 is a block-like member that is fitted into the guide recess 13 of the chuck body 5, and has a substantially convex shape that protrudes at the front end side so as to fit into the first recess 13 a and the second recess 13 b. (The shape seen from the radial direction is a convex shape).

  A groove 19 is formed on the distal end side of the moving member 17 perpendicular to the radial direction. Then, a convex portion 21 on the rear end side of the chuck member 15 to be described later is fitted into the groove 19 so that the chuck member 15 and the moving member 17 are positioned so as not to be displaced, and is fixed integrally with the chuck member 15 by a screw 18. Has been.

  As shown in FIG. 3, the three chuck portions 7 (and hence the chuck member 15) are radially arranged at an angle of 120 ° in the radial direction about the central axis O of the chuck body 5 that is the fixed position of the workpiece 3. They are arranged at equal intervals and can move back and forth in the radial direction (that is, along the radiation line A toward the central axis O).

In particular, in this embodiment, the front end surface 23 that is a surface for holding the workpieces 3 of all the chuck members 15 has a predetermined angle α (for example, 60 °) with respect to the moving direction of the chuck members 15 (that is, the radiation line A). Inclined. Further, the tip surfaces 23 of all the chuck members 15 are inclined in the same direction with respect to the moving direction inward in the radial direction.
Specifically, the inclination direction of the front end surface 23 of all the chuck members 15 is in each radial direction inward when viewed from the front end surface 5a side of the chuck body 5 (ie, the front side in FIG. 3). The right side is set so as to protrude toward the center axis O (that is, to the right). On the contrary, all the front end surfaces 23 may be set downwardly to the right.

As the predetermined angle α, for example, a range of 60 ° ± 10 ° can be mentioned.
Therefore, the tip surface 23 (and its extended surface) of the three chuck members 15 forms a triangle (here, a regular triangle), and the center of the triangle (the center of the inscribed circle) is the fixing position of the workpiece 3. That is, it coincides with the central axis O of the chuck body 5 and the workpiece 3.

Here, the shape of the chuck member 15 will be described in more detail.
As shown in FIGS. 4 and 5, the chuck member 15 is a plate-like member, and protrudes from the main body portion 25 having a substantially rectangular parallelepiped shape to the side in contact with the workpiece 3 (right side in FIG. 5). A projection portion 27 having a substantially triangular prism shape is provided, and the surface of the projection portion 27 on the workpiece 3 side is a flat tip surface 23.

Further, a convex portion 21 that fits into the groove 19 of the moving member 17 is formed across the width direction of the main body portion 25 on the moving member 17 side (upper side in FIG. 4) of the main body portion 25.
Further, the chuck member 15 is fixed to the moving member 17 so as to penetrate the main body portion 25 in the height direction (vertical direction in FIG. 4) on both sides of the convex portion 21 in the main body portion 25 (see above). A pair of screw holes 29 are formed in which the screw 18 is screwed.

Further, a chamfered portion 31 that is cut obliquely is provided on the front end side (lower side in FIG. 4) of the protruding portion 27 of the chuck member 15 so as not to damage the workpiece 3 when it contacts the workpiece 3.
As shown in FIGS. 1 to 3, on the side surface of the chuck body 5, as a moving mechanism 9 by air pressure, each chuck portion 7 is moved inside the chuck body 5 so as to move to the central axis side of the chuck body 5. A first air pipe 33 that supplies air to the chuck body 5 and a second air pipe 33 that supplies air into the chuck body 5 are connected so as to move the chuck portion 7 away from the central axis of the chuck body 5. Yes. Note that the air flow path and the like inside the chuck body 5 for movement are the same as in the prior art, and the description thereof is omitted.

b) Next, the operation of the chuck device 1 will be described with reference to FIGS.
First, as shown in FIG. 8, the workpiece 3 held by the chuck device 1 of the present embodiment is an oxygen sensor 3 that detects an oxygen concentration. The oxygen sensor 3 includes a cylindrical metal metal shell 39 and a metal shell 39. A detection element (not shown) that is fixed inside the metal shell 39 and protrudes from the front end side (gas measurement side: upper side of FIG. 8), and a hollow cylinder that covers the front end side of the detection element A metal protector 41 (for example, made of SUS310S) and an outer cylinder 43 extending from the rear end side of the metal shell 39 are provided.

  The protector 41 is a bottomed, thin-walled (for example, 0.5 mm thick) cylindrical member whose front end is closed, and is joined at its predetermined position X on the front end side of the metal shell 39 by welding. .

Next, a procedure for holding and transferring the oxygen sensor 3 will be described.
As shown in FIG. 6A, first, the oxygen sensor 3 is arranged on the base 45 so that the protector 41 on the tip side is on the upper side. On the other hand, the chuck device 1 is disposed above the oxygen sensor 3 with the front end surface 5a of the chuck body 5 facing downward. The chuck device 1 is arranged so that the center axes of the chuck body 5 and the oxygen sensor 3 are aligned.

  Since this time is before holding the oxygen sensor 3, as shown in FIG. 7, by sending air to the second air pipe 35, each moving member 17 (and hence each chuck member 15) is moved in the radial direction. It moves to the outer side and the space (space where the protector 41 is inserted) 47 of each chuck | zipper member 15 is ensured. That is, each chuck member 15 is opened.

Next, as shown in FIG. 6B, with each chuck member 15 open, the chuck device 1 is lowered and the protector 41 is placed in the central space 47 of each chuck member 15.
At this time, as shown in FIG. 8, the chuck device 1 is arranged such that the tip surface 23 of each chuck member 15 is located above a predetermined position X where the protector 41 is joined.

  Next, as shown in FIG. 6C, by sending air to the first air pipe 33, each chuck member 15 is moved inward in the radial direction, and the protector 41 is moved by the three chuck members 15. Hold from 3 directions.

  Specifically, as shown in FIG. 9, each chuck member 15 is moved radially inward toward the central axis O, and the outer peripheral surface of the protector 41 is pressed by the tip surface 23 of each chuck member 15. Hold the protector 41 and hold it.

At this time, as shown in FIG. 10, the front end surface 23 of each chuck member 15 is in contact above the predetermined position X where the protector 41 is joined.
Next, as shown in FIG. 6 (d), with the protector 41 (and hence the oxygen sensor 3) held by the chuck member 15, the chuck device 1 is moved upward to move in a predetermined direction (for example, left and right direction). The oxygen sensor 3 is transported.

c) Next, the effect of the chuck device 1 of this embodiment will be described.
In the chuck device 1 of the present embodiment, the tip surfaces 23 of the chuck members 15 that are in contact with the protectors 41 of the oxygen sensor 3 are not perpendicular to the moving direction of the chuck members 15 as in the prior art. When viewed from the direction (for example, the front side in FIG. 3), they are inclined in the same direction with respect to the moving direction radially inward.

  Therefore, when the protector 41 is held, when the chuck member 15 is brought close to the protector 41, the protector 41 moves while being pressed by the tip surface 23 of the chuck member 15, but the tip surface 23 is moved in the moving direction. Since it is formed obliquely, the protector 41 tends to move slightly obliquely from a predetermined fixed position (that is, the central axis O of the chuck body) initially arranged. At this time, since the protector 41 is similarly pressed by the chuck member 15 from three directions, as a result, the forces in the pressing direction are balanced and the protector 41 is held at a predetermined fixed position.

  Further, if there is a dimensional error in the chuck body 5, the chuck unit 7, or the oxygen sensor 3, only the two-way chuck member 15 comes into contact with the protector 41 first, and the two-way chuck member 15 Even when the protector 41 is about to be held, the front end surface 23 of the chuck member 15 is inclined in the same direction, so that the protector 41 moves in the direction in which the protector 41 is pushed out from between the two directions of the chuck member 15. The two chuck members 15 are pressed. Therefore, the holding by only the two-direction chuck member 15, that is, the so-called two-point holding hardly occurs, and the chuck member 15 is always held by the three-way chuck member 15.

  In other words, in the present embodiment, the protector 41 is held such that the front end surfaces 23 of the three chuck members 15 form a triangle (particularly a regular triangle), so that the protector 41 (and hence the oxygen sensor 3) is always held securely. be able to.

For this reason, it is possible to effectively prevent the oxygen sensor 3 from being dropped and the oxygen sensor 3 from being stopped due to such two-point holding particularly during the transportation of the oxygen sensor 3.
Moreover, in this embodiment, since the protector 41 is not pressed by the surface perpendicular | vertical to a moving direction like the past, even when the protector 41 is formed with the thin metal plate, the advantage that the protector 41 cannot be damaged easily. There is.

  Further, in the present embodiment, the chuck member 15 holds the protector 41 at other than the uneven connection portion (predetermined portion X) where the protector 41 is welded to the metallic shell 39. There is an advantage that the oxygen sensor 3 can be held.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects.

  For example, the workpiece includes not only an oxygen sensor but also various sensors having a hollow cylindrical member (such as a protector) at a holding position, such as a temperature sensor.

1 ... Chuck device 3 ... Work (oxygen sensor)
DESCRIPTION OF SYMBOLS 5 ... Chuck main body 7 ... Chuck part 15 ... Chuck member 17 ... Moving member 23 ... Tip surface 41 ... Protector

Claims (4)

The chuck body,
Three chuck members disposed on the front end side of the chuck body and holding a hollow cylindrical metal workpiece;
With
In the chuck device for holding the work by moving the chuck member from the radially outer side to the inner side in the radial direction with respect to the center axis of the work with respect to the work arranged at a predetermined position,
The tip surfaces of all the chuck members that contact the workpieces are inclined in the same direction with respect to the moving direction inward in the radial direction when the workpieces are viewed from the axial direction. Chuck device.   The chuck device according to claim 1, wherein a triangle is formed by tip surfaces of the three chuck members when the workpiece is viewed from the axial direction.   The said workpiece | work has a connection location where the 1st member and the 2nd member were connected, The said chuck member hold | maintains the said workpiece | work in the location different from the said connection location. The chuck apparatus as described.   The chuck device according to claim 1, wherein the workpiece is a sensor having a protector.

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