JPS6338026Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a workpiece positioning device that fixes a cylindrical workpiece using claws and thereby positions the workpiece.

BACKGROUND ART Conventionally, in a workpiece processing process such as a pressing process or a machining process for a cylindrical workpiece, it is first necessary to fix and position the workpiece at a predetermined location of a processing machine prior to each process. In many cases, for such positioning of a cylindrical workpiece, multiple claws provided on the machine are moved from the outer peripheral side of the cylindrical workpiece in the radial direction of the workpiece. Move toward the center to grab the outer circumferential surface of the workpiece, or conversely move multiple claws outward in the radial direction of the workpiece from the inner circumferential side of the workpiece to grasp the inner circumferential surface of the workpiece. A chuck mechanism is used.

Conventionally, there has been a chuck mechanism in which a plurality of chucks are manually moved, but this requires time just for fixing and positioning the workpiece, which impairs work efficiency. In addition, since it was done manually, there were variations in the force with which the work was pressed, resulting in damage to the work. Particularly in the case of thin-walled workpieces, the pressing force may be too strong and cause deformation.

In the case of a chuck that uses hydraulic pressure or air, it does not have the above disadvantages, but it requires a separate hydraulic unit or special piping for hydraulic pressure or air, and the structure of the entire device related to the chuck is somewhat complicated. Therefore, it became a factor that hindered the realization of lower prices of the equipment.

This invention was made in order to eliminate the above-mentioned drawbacks, and its main purpose is to create a workpiece positioning device that has a very simple structure, yet reliably fixes a cylindrical workpiece and thereby positions the workpiece. The goal is to provide the following.

Simply put, this invention is a device equipped with a chuck member having a plurality of claws and an axial positioning member for stopping the workpiece from moving backward in the axial direction, When a load from the above-mentioned axial positioning member is applied to the claws through the workpiece, each claw rotates about a certain point as a fulcrum, thereby causing each claw to move around the inner circumference of the workpiece. The surface is pressed outward in the radial direction, and as a result, the cylindrical workpiece can be fixed and positioned by the plurality of claws.

The above objects and other objects and features will become more apparent from the following detailed description taken in conjunction with the drawings.

FIG. 1 is a front view showing a workpiece positioning device which is an embodiment of this invention, and main parts are shown in cross section to clarify its structure. The illustrated workpiece positioning device positions a cylindrical workpiece 1 as shown in FIG. The workpiece 1 is rotated around the axis of the workpiece 1 to align its directions so that a certain point on the outer peripheral surface of the workpiece 1 is always located at the same position.

Here, it is necessary to align the directions of the cylindrical workpiece 1 for the following reason. That is, the cylindrical workpieces 1 whose directions have been aligned are sent to the next process while maintaining their aligned state. In the next step, for example, a liquid level display window is formed for viewing the liquid level in the jar pot located at a certain location on the outer peripheral surface of the cylindrical workpiece 1. This liquid level display window is displayed when the cylindrical workpiece 1 shown in FIG.
When cut into individual sector shapes, holes 2 for liquid volume display windows are punched at certain locations. Similarly, a notch 3 is provided at a certain location on the rear end of the fan-shaped workpiece 1. Thereafter, the sector-shaped workpiece 1 is rolled up so that its generating lines 4 and 5 touch each other, and becomes a cylindrical workpiece 1 as shown in FIG. In this way, in the next step, the liquid level display window 2 provided on the cylindrical workpiece 1 is finished, and the finishing jig is always kept at a constant position relative to the cylindrical workpiece 1. Since the jig is automatically transported, it is necessary to position the window 2 for displaying the liquid amount at the position where the jig is to be transported. Therefore, by the device shown in FIG. 1, the cylindrical workpiece 1 is rotated so that its liquid volume display window 2 is always located at a constant position, and the liquid volume display window 2 reaches a predetermined position. When this occurs, the rotation is stopped. The mechanism will become clear from the explanation below.

The workpiece positioning device shown in FIG.
and an axial positioning member 7 located on the rear end side of the cylindrical workpiece 1. The chuck member 6 and the axial positioning member 7 are each movable in the axial direction of the cylindrical workpiece 1.
In FIG. 1, the cylindrical workpiece 1 is already attached to the chuck member 6.
The state shown is that the device is installed between the device and the axial positioning member 7, and the following operations were performed to reach this state. That is, the chuck member 6 is located further to the left than the position shown in FIG. 1, and the axial positioning member 7 is located further to the right than the position shown in FIG. In this way, in a position where both the chuck member 6 and the axial positioning member 7 are retracted from each other from the position shown in FIG. The length of the workpiece 1 in the axial direction is larger than the length of the workpiece 1 in the axial direction. In this state, the cylindrical workpiece 1
is carried between the chuck member 6 and the axial positioning member 7 by a loading device (not shown), and when the cylindrical workpiece 1 is in that position, the chuck member 6 is moved toward the right in FIG. It moves forward and stops at a position where it comes into contact with the front end of the cylindrical workpiece 1. Similarly, the axial positioning member 7
In the figure, it moves forward to the left and stops at a position where it supports the rear end of the cylindrical workpiece 1. FIG. 1 shows the cylindrical workpiece 1 mounted between the chuck member 6 and the axial positioning member 7 in this manner. Further, as is clear from the figure, the respective central axes of the chuck member 6, the axial positioning member 7, and the cylindrical workpiece 1 coincide with each other.

First, the structure of the chuck member 6 will be explained below. The chuck members 6 include a base 10 which rotates by driving from a drive source via a shaft 9, and are arranged radially around a central axis on the base surface of the base 10, as shown in FIG. It has a plurality of claws 11. In this embodiment, the plurality of claws 11 are divided into 12 parts as shown in FIG. 4, and the shape of each part is shown in a perspective view in FIG.

The shape of the claw 11 and the attachment of the claw 11 to the base 10 will be explained using FIG. 7 while referring to FIG. 5. The claw 11 has a smoothly curved protrusion 12 at its bottom, and has a through hole 13 at a position further toward the central axis from the position where the protrusion 12 is provided. Also nail 1
1 is a workpiece front end support part 14 that comes into contact with the front end of the cylindrical workpiece 1, as clearly shown in FIG.
and a work pressing portion 15 located close to the inner circumferential surface of the cylindrical work 1. As shown in the figure, the base 1 is formed with a recess 16 for receiving the protrusion 12 of the claw 11, and is further provided with a pin 17 to be inserted into the through hole 13 of the claw 11. Here, as shown in the figure, the diameter of the pin 17 must be selected so that the inner peripheral surface of the through hole 13 of the claw 11 and the outer peripheral surface of the pin 17 are located with a certain distance. .

In this way, the claw 11 has its protrusion 12 connected to the base 10.
The pin 17 is located in the recess 16 of the base 10 and the through hole 13 of the claw 11 is provided in the base 10.
is arranged on the base surface of the base 10 so as to receive the. In order to prevent the claw 11 from separating from the base 10, a claw presser 18 shown in a perspective view in FIG. 6 presses one end of the claw 11 located on the central axis side onto the base surface of the base 10. and attached to the base 10.
The attachment of this pawl holder 18 to the base 10 is carried out at the seventh
As is clear from the figure, the through hole 19 of the pawl holder 18
This is done by a pawl retainer mounting bolt 20 inserted into the holder. Further, as shown in the figure, a spring 22 is provided between the head 21 of the pawl retainer mounting bolt 20 and the pawl retainer 18.
is provided. Due to the action of this spring 22, the claw presser 18 is always pressed against the base surface of the base 10.

Returning to Figure 1, the drive from the drive source is based on 10
One end of the shaft 9, which transmits power to the drive shaft 9, is shown broken away in FIG. 1, but FIG. 1a shows how the drive source and the shaft 9 are connected. In the figure, the drive source for rotating the base 10 is a rotor 23. This rotor 23 rotates by a certain fixed angle. A gear 24 is attached to the shaft of the rotor 23 and extends relatively long along the axial direction of the shaft. A gear 25 that meshes with this gear 24 is attached to the shaft 9. In this way, the rotation of the rotor 23 is transmitted to the shaft 9, and the base 10 attached to the other end of the shaft 9 rotates. The relatively long shape of the gear 24 in the axial direction is to prevent the gears 24 and 25 from becoming disengaged even if the shaft 9 moves a minute distance in the axial direction together with the gear 25.

This movement of the shaft 9 by a minute distance in the axial direction is achieved by the following configuration. This will be explained using FIG. As shown, the shaft 9
A cylinder 26 having a piston rod as a part of the shaft 9 is inserted therethrough. A piston 2 is mounted on the shaft 9 so as to divide the internal space of the cylinder 26 into two.
7 is installed. In this way, the internal space of the cylinder 26 is divided into a left space 28 and a right space 29.
Ventilation holes 30 and 31 are provided in the respective spaces 28 and 29, and these ventilation holes 30
and 31 are connected to a directional switching valve 32.
If air is sent to the left space 28 through the vent 30 in this way, the shaft 9 moves to the right in FIG. 1 together with the piston 27, and the right space 2
If air is supplied to the shaft 9 through the vent 31, the shaft 9 will move to the left in FIG. 1 together with the piston 27. As the shaft 9 moves in the left-right direction in FIG.
The base 10 attached to the shaft 9 is also the first
In the figure, it will move in the left and right direction.

Next, the structure of the axial positioning member 7 located at the rear end side of the cylindrical work 1 in Fig. 1 will be described. The axial positioning member 7 has a work rear end support part 33 that contacts the rear end of the cylindrical work 1, and further has a shaft 34 that extends long along the central axis of the axial positioning member 7. A positioning bolt 8 is attached to the tip of the shaft 34 by screwing as shown in the figure. When the cylindrical work 1 shown in Fig. 1 is mounted between the chuck member 6 and the axial positioning member 7, the distance between the head surface of the positioning bolt 8 facing the chuck member 6 and the tip surface of the shaft 9 to which the chuck member 6 is attached is adjusted so as to be close. This distance is adjusted by rotating the positioning bolt 8 clockwise or counterclockwise relative to the tip of the shaft 34.

In addition, with reference to FIG. 9 showing a view of the axial positioning member 7 of FIG. 1 viewed from below, a portion of the work rear end support portion 33 of the axial positioning member 7 is cut. A notch 35 is provided. A stopper 36 is attached to the axial positioning member 7 so as to be movable along the notch 35 in the direction of the central axis. As shown in FIG. 1, the stopper 36 has an L-shape and is attached to the axial positioning member 7 via a spring holding pin 37. The spring retainer pin 37 extends through the axial positioning member 7 and is slidable along a hole in the axial positioning member 7 that receives the spring retainer pin 37 . And the spring holding pin 37 is the head 3 at one end of the spring holding pin.
8 and the axial positioning member 7, a force is always applied in the direction in which the chuck member 6 is located. Therefore, when the cylindrical workpiece 1 is not attached, the stopper 36 moves in the direction in which the chuck member 6 is located along the notch 35 of the workpiece rear end support part 33, as shown in FIG. In other words, the position is shifted to the left in the figure.

The strength of the force of the spring 39 that always applies a force to the stopper 36 in the left direction is weaker than the force of the spring 22 that presses the pawl 11 of the chuck member 6 mentioned above against the base surface of the base 10. It is. Therefore, in order to be in the state where the cylindrical workpiece 1 shown in FIG. 1 is mounted, the axial positioning member 7 moves forward from a position further to the right than the position shown in FIG. At this time, since the position of the stopper 36 at that time is as shown in FIG. 10, the front end 40 of the stopper 36 first comes into contact with the rear end of the cylindrical workpiece 1. If the axial positioning member 7 moves further leftward in this state, the front end of the cylindrical workpiece 1 is stopped by the workpiece front end support part 14 of the claw 11 of the chuck member 6, so that the stopper 36
The axial positioning member 7 moves forward to the left against the force of the spring 39 while stopping at a position where its front end 40 is in contact with the rear end of the workpiece 1. The state in which the axial positioning member 7 has advanced to a predetermined position is the state shown in FIG. In this state, the rear end of the cylindrical work 1 is in contact with both the front end 41 of the work rear end support part 33 and the front end 40 of the stopper 36.

The workpiece positioning device having the above configuration fixes and positions the cylindrical workpiece 1 from the inner circumferential surface side of the cylindrical workpiece 1 shown in FIG. The operation of arranging the directions so that one point is always at a constant position will be described below.

In the state shown in FIG. 1, air is supplied from an air source indicated by A to the left space 28 of the cylinder 26 through the vent 30 of the cylinder 26. As a result, the shaft 9 moves to the right in FIG.
Its movement is stopped by contacting the head of the object.

FIGS. 7 and 8 clearly show the changes in the chuck member 6 between the state before the shaft 9 moves and the state after the shaft 9 moves. Figure 7 shows the state before the shaft 9 moves, and Figure 8 shows the shaft 9.
This is the state after moving to the right. Before the shaft 9 moves to the right, as shown in FIG. 7, the claw 11 is prevented from rotating by the action of the claw presser 18 which is biased by the spring 22.

However, when the shaft 9 moves to the right, the rear end of the cylindrical workpiece 1 is stopped by the axial positioning member 7, so the claw 11
A load is applied to the workpiece front end support portion 14 along the generatrix direction of the workpiece 1 in the left direction in the figure. As this load is applied to the workpiece front end support portion 14 of the claw 11, the claw 11 rotates clockwise in FIG. 7 about the protrusion 12 at the bottom thereof as a fulcrum. Along with this rotation, the claw presser 18 moves in a direction away from the base surface of the base 10 so as to resist the force of the spring 22 and compress the spring 22.

In this way, the state after the shaft 9 is moved is as shown in FIG. 8. and Figures 7 and 8.
As is clear from a comparison of the figures, the workpiece pressing portion 15 of the claw 11, which was close to the cylindrical workpiece 1 before the claw 11 rotated, is moved to the cylindrical workpiece 1 by the rotation of the claw 11. It can be seen that the inner circumferential surface of the workpiece 1 is in contact with the inner circumferential surface of the workpiece 1, and the inner circumferential surface is pressed outward in the radial direction. The claws 11 are arranged radially on the base surface of the base 10, and each claw 11 contacts the inner circumferential surface of the workpiece 1 and presses it outward, so the workpiece 1 is held in place by the chuck. It is fixed to member 6 and positioned.

As mentioned above, the cylindrical workpiece 1 is held by the plurality of claws 11.
If the rotor 23 shown in FIG. 1a is driven while the workpiece 1 is positioned by the chuck member 6, the workpiece 1 will rotate together with the chuck member 6. A notch 3 is provided at the rear end of the workpiece 1, as described above and as shown in FIG. In FIG. 9, the workpiece 1 and the notch 3 of the workpiece 1 are shown by dashed lines, and the notch 3 moves on the front end 41 of the workpiece rear end support part 33 as the workpiece 1 rotates. When this notch 3 reaches the position of the front end 40 of the stopper 36, the stopper 36 is biased leftward in the figure by the spring 39 as shown in FIG. It moves to the left and engages with the notch 3 of the workpiece 1.

Here, the movement of the stopper 36 to the left is the first
This is detected by limit switch 42 as shown in the figure. And this limit switch 42
is connected via an electromagnetic switch 43 to the solenoid 1 of the directional valve 32 that controls the direction of air to the cylinder. This limit switch 42,
A contact circuit diagram of the electromagnetic switch 43 and the solenoid 1 of the directional switching valve 32 is shown in FIG.

Its operation will be explained with reference to FIGS. 1 and 11. When the stopper 36 begins to move to the left, the stopper 36 will come into contact with the limit switch 42. This contact closes the contact point of the limit switch LS, which is the a contact point, thereby exciting the coil 1CR of the electromagnetic switch 43.
Accordingly, the a contact 1CR closes, thereby energizing the solenoid SOL1 of the directional control valve 32.
Therefore, the directional valve 32 shown in FIG.
The valve position of the air source A is switched, and the air from the air source A is passed through the vent 31 of the cylinder 26 to the right space 29.
supplied to Therefore, shaft 9 is piston 2
It will move to the left along with 7. With this movement of the shaft 9 to the left, the load applied to the workpiece front end support portion 14 of the claw 11 is loosened, and the claw 11 is therefore moved from the claw presser biased by the spring 22. By the action of 18, the state shown in FIG. 1 is restored. By this rotation of the claw 11 to the return state, the pressing of the workpiece inner peripheral surface by the workpiece pressing portion 15 of the claw 11 is released.

In this way, when the rotation of the cylindrical workpiece 1 is stopped by engaging the notch 3 with the stopper 36 provided on the axial positioning member 7, only the chuck member 6 rotates. become. As described above, work 1 is
Its rotation is always stopped at the position where the notch 3 provided at the rear end of the axial positioning member 7 engages with a stopper 36 provided on the axial positioning member 7.
As described above with reference to FIG. If the notches 3 of 1 are always oriented at the same position, the holes 2 for the liquid volume display window will also always be aligned at a constant position.

In the above-mentioned example, when the rotation of the workpiece 1 is stopped by the stopper 36, the shaft 9 on which the chuck member 6 is attached moves backward by the action of air, thereby causing the claw 11 and the inner circumference of the workpiece 1 to move backward. Avoiding friction with surfaces. However, another mechanism that utilizes the friction between the claw 11 and the inner circumferential surface of the workpiece 1 can be considered. FIG. 12 shows its block diagram. That is, it is conceivable to provide a slip mechanism that causes the rotor to slip when a predetermined load or more is applied between the rotor and the shaft to which the chuck member is attached. In this case, when no resistance force is applied to the rotation of the shaft, the drive for rotation of the rotor is directly transmitted to the shaft. However, when the rotation of the workpiece is stopped by the stopper as described above, the claw of the chuck member attached to the shaft attempts to rotate while still pressing the inner peripheral surface of the workpiece. At this time, a frictional force against rotation is generated between the pawl and the inner circumferential surface of the workpiece, and this frictional force acts on the slip mechanism, causing the shaft to stop without rotating. Only the rotor continues to rotate.

In the embodiments described above, the workpiece is a thin cylindrical workpiece with a circular cross-sectional shape used in a jar pot, but the present invention is not limited to such a workpiece. That is, the workpiece may be thick, or may be a cylindrical workpiece whose cross-sectional shape is not circular but polygonal.

Further, although the workpiece positioning device shown in the embodiment has a mechanism in which the chuck member rotates, it is not necessary to rotate in such a manner when the purpose of this invention is considered. Similarly, in the embodiment, the stopper 36 is provided on the axial positioning member, but the workpiece positioning device may have no such stopper.

As described above, according to this invention, the plurality of claws are rotated by applying a load to the plurality of claws through the cylindrical workpiece. Since the mechanism is to press the inner peripheral surface of the workpiece to fix the workpiece, the structure of the workpiece positioning device is extremely simple, and the cost of the device can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a workpiece positioning device which is an embodiment of this invention, and its main parts are shown in sectional view. FIG. 1a is a diagram showing the rotational drive transmission state between the rotor and the shaft. FIG. 2 is a perspective view of a cylindrical workpiece used in explaining an embodiment of this invention. FIG. 3 is a plan view showing the state before the cylindrical workpiece shown in FIG. 2 is made into a cylindrical shape. FIG. 4 is a plan view showing a state in which a plurality of claws are arranged radially. FIG. 5 is a perspective view of the claw. FIG. 6 is a perspective view of the pawl holder. 7 and 8 are cross-sectional views showing the mechanism of the chuck member, and FIG. 7 shows the state before the claw rotates;
FIG. 8 shows the state after the claw has rotated. 9 and 10 are front views showing the axial positioning member, FIG. 9 shows the stopper moving against the force of the spring, and FIG. 10 shows the stopper moving against the force of the spring. FIG. 6 is a diagram showing the state in the position indicated by the function. FIG. 11 is a contact circuit diagram showing the operating conditions of the limit switch, electromagnetic switch and directional switching valve. FIG. 12 is a block diagram for explaining the slip mechanism. In the figure, 1 is a workpiece, 2 is a hole for a liquid level display window, 3 is a notch, 6 is a chuck member, 7 is an axial positioning member, 9 is a shaft, 10 is a base,
11 is a pawl, 12 is a protrusion, 14 is a workpiece front end support, 15 is a workpiece presser, 16 is a recess, 18 is a pawl holder, 26 is a cylinder, 33 is a workpiece rear end supporter, and 36 is a stopper.

Claims (1)

[Claims for Utility Model Registration] (1) Located on the front end side of a cylindrical workpiece, it has a base and a plurality of claws arranged radially around the axis of the workpiece on the base surface of the base. a chuck member; and an axial positioning member for abutting against a rear end of the workpiece to stop the workpiece from moving backward in the axial direction; each of the claws is movable relative to the axial direction of the workpiece, and each of the claws has a rotation axis extending perpendicularly to a radial direction centered on the axis of the workpiece and parallel to the base surface. each claw is rotatably provided, and each of the claws has a workpiece front end support part that can come into contact with the front end of the workpiece, and a workpiece pressing part that can come into contact with the inner circumferential surface of the workpiece, and the chuck member and By relatively approaching the axial positioning member, a load from the axial positioning member is applied to the workpiece front end support portion of the claw through the workpiece, thereby causing the claw to rotate. A workpiece positioning device in which the workpiece pressing section presses an inner circumferential surface of the workpiece outward in a radial direction to fix the workpiece. (2) The workpiece positioning device according to claim 1, which is provided with a spring that returns the pawl to its pre-rotation state when the load applied to the front end support portion of the workpiece is released. . (3) A pawl holder is provided that contacts one end of the pawl and presses the one end of the pawl in the forward direction of the workpiece, and is always urged in the forward direction of the workpiece by a spring. A workpiece positioning device according to claim 1 or 2 of the utility model registration claim. (4) The workpiece positioning device according to any one of claims 1 to 3, wherein the chuck member is rotatable around the axis of the workpiece.