JPH0577130A - Positioning device for work piece having eccentric part - Google Patents

Abstract

PURPOSE:To surely execute the alignment of a workpiece by abutting the eccentric part of a workpiece on a rotational direction guide to rotate round a journal, and after the workpiece is positioned in the direction of rotation to a certain extent, sandwichedly holding it between the first and second centering members for positioning the axial center of the work piece in a vertical direction. CONSTITUTION:A pair of rotational direction guides 2, 2 confronting each other at an interval being about the same as the width of an eccentric pin part 1c is arranged between the first and the second centering member 5, 6 sandwichedly holding both the ends of a workpiece 1. A work holder 3 softly holds the workpiece 1 between the centering members 5, 6 and carrys it in. In this case, when positional dislocation occurs at the workpiece 1, the eccentric pin part 1c abuts on the rotational direction guides 2, 2 and rotates round a journal 1a, and after the workpiece is positioned in the direction of rotation to a certain extent, the first and the second centering member 5, 6 sandwichedly holds the workpiece to complete its positioning in an axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for a work having an eccentric portion, for example, a crank-shaped work. More specifically, the present invention relates to a positioning device for positioning a work having a journal portion, a crank arm, and an eccentric pin portion eccentric with respect to the journal portion at a reference position for machining or the like.

[0002]

2. Description of the Related Art Conventionally, in positioning a work having an eccentric portion such as a crank shaft, a position where the dimensions of a crank arm have little variation is used as a proof for positioning, and the positioning is performed. For example, as shown in FIG. 10, a contact 105 that is parallel to the tangent line of the journal 102 is installed along the journal 102 of the work 101, and the crank arm 103 is connected to the actuator 106 from the opposite side.
The crank arm 103 is rotated around the journal portion 101 and pressed against the hammer 105 to be positioned at a predetermined position. In this state, the journal part 102 is clamped and the work 101 is rotated at a predetermined angle to perform a predetermined process.

[0003]

However, according to this method, in the case of a work in which the crank arm 103 of the work 101 is small and the eccentric pin 104 has a small eccentric amount, even if the crank arm 103 or the eccentric pin portion 104 is pushed by the actuator 106. Since the generated rotation moment is smaller than the frictional force supporting the work, the work cannot be rotated around the work journal portion. Also,
Since the crank arm 103 has a large dimensional variation and cannot be used as a proof of rotational positioning, only the eccentric pin portion exists as a proof of rotation, and the conventional method cannot perform rotational positioning.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a positioning device for positioning a work having a small crank arm and a small amount of eccentricity in the rotational direction only by the journal portion and the eccentric pin portion.

[0005]

In order to achieve the above object, a positioning device for a work having an eccentric portion according to the present invention comprises:
In a positioning device for positioning a work having a journal portion, a crank arm, and an eccentric pin portion eccentric with respect to the journal portion at a reference position for machining or the like, a pair of facing members are arranged at intervals of substantially the same width as the eccentric pin portion. The eccentric pin portion is movably held by applying an external force to the journal portion of the work by relative movement between the rotation direction guide and the rotation direction guide, and the eccentric pin portion is arranged between the radial guide member and the radial guide member. A work holder to be installed in
An axial positioning portion that axially contacts the crank arm of the work introduced between the rotation direction guides to axially position the work, and an eccentric pin for the work introduced between the rotation direction guides. The first and second centering members which are fitted in the center holes respectively provided in the end faces of the parts and the end faces of the journal parts to hold the work, and only when the work is released from the work holder. It is configured to include a clamp portion that holds the journal portion when it is held.

[0006]

Therefore, when the work is held in the work holder with the eccentric pin portion being displaced in the rotational direction, the width of the eccentric pin portion is almost the same when the eccentric pin portion is inserted between the rotation direction guides. It is regulated to fit inside and rotates around the journal part as an axis, and is positioned at a substantially constant position. That is, since the eccentric pin portion contacts the rotation direction guide and rotates around the journal, positioning in the rotation direction is performed to some extent. Therefore, if the first and second centering members are fitted in the center holes at both ends of the work and the fixing of the journal portion by the work holder is released, the work is held by the first and second centering members and the shaft centers are aligned. At the same time, the center of gravity is rotated so that the center of gravity is located on the perpendicular line passing through the centering center, and the axial center of the work and the position in the rotation direction are determined. Then, in this state, the axial positioning portion is brought into contact with the crank arm, whereby the axial positioning of the work is also performed. In this state, the work is positioned at a fixed position by clamping the journal part.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to the embodiments shown in the drawings.

1 to 9 show an embodiment in which the work positioning device of the present invention is implemented. This embodiment is an apparatus for positioning and clamping a workpiece in preparation for machining at each machining station in a machining unit that sequentially conveys a workpiece to a plurality of machining stations by a line type transfer and performs a series of machining.

This apparatus comprises a pair of rotation direction guides 2 facing each other at an interval of substantially the same width as the eccentric pin portion 1c of the work 1.
2 and the journal portion 1a of the work 1 are rotatably held and lifted toward the rotation direction guides 2 and 2 eccentric pin portion 1
The workpiece holder 3 for introducing c between the radial guide members 2 and 2 and the crank arm 1b of the workpiece 1 introduced between the rotation direction guides 2 and 2 are axially contacted to position the workpiece in the axial direction. A center hole 1e and a journal portion 1a opened at the end surface of the eccentric pin portion 1c of the work 1 introduced between the axial positioning portion 4 and the rotation direction guides 2 and 2.
The first and second centering members 5 and 6 fitted in the center hole 1d on the end face of the work holder 3 and the work 1
And clamped only by both centering members 5 and 6 to clamp the journal 1a when rotation and axial positioning are completed.
When the work 1 carried in by the direct transfer part 10 is lifted while the journal 1a is lightly held by the work holder 3, the eccentric pin part 1c is inserted into the rotation direction guides 2 and 2 so that the positioning in the rotation direction is performed to some extent. After that, the first and second centering members 5 and 6 are clamped to perform axial positioning and re-rotational positioning.

As shown in FIG. 3B, the work 1 has a journal portion 1a, a crank arm 1b and a journal portion 1a.
On the other hand, it is a round component having an eccentric pin portion 1c that is eccentric, and center holes 1d and 1e are opened in the end faces of the journal portion 1a and the eccentric pin portion 1c.

The direct transfer unit 10 is shown in FIG.
As shown in FIG. 9, the transfer bars 12, 1 are moved back and forth by an actuator, for example, a hydraulic cylinder 11.
2 and work receiving portions 13 and 13 installed on the bars 12 and 12 for supporting the work 1. The transfer bar 1 is operated by the operation of the hydraulic cylinder 11.
The workpieces 1 and 1 are provided so as to be carried into the processing station by horizontally moving the workpieces 2 and 12 by a predetermined amount. The transfer bars 12, 12 are slidably supported by the guide rods 43, 43 via sliders 44, 44. This direct transfer unit 10
In the case of the present embodiment, the work transfer means 14 is provided at the same interval as the moving stroke of the transfer bar 12 on the way to the processing station, and the work 1 horizontally moved by a certain amount is temporarily lifted from the work receiving portion 13. In the meantime, after returning the transfer bar 12 to the original position, the work transfer means 14 is activated again to lower the work 1.
Another work receiving part 1 different from that before lifting the work 1.
It is provided so that the work 1 is fed by a constant amount by transferring the work 1 to the work 3. The work receiving portion 13 is, for example, as shown in FIG.
As shown in FIG. 3, the direct transfer portion 1 having a U-shaped groove 15 for supporting the journal portion 1a of the work 1
In the case of this embodiment, 0 is a pair of two works 1 and 1 which are simultaneously transferred to the processing station. Further, the work transfer means 14 includes two sets of work receiving portions 16 and 16 having the same shape as the work receiving portion 13, a pedestal 17 on which the work receiving portions 16 and 16 are mounted at predetermined intervals, and an actuator for supporting and raising and lowering the pedestal 17, for example, a hydraulic cylinder 18. It consists of and. Incidentally, reference numeral 19 is a mount.

The work holder 3 lifts the two works 1 and 1 carried into the processing station by the direct transfer unit 10 and transfers them between the first and second centering members 5 and 6. It constitutes a part of the positioning device. This work holder 3
Are, for example, chucks 20 and 2 that lightly hold the work 1 so that the work 1 can be moved when an external force of a certain magnitude is applied.
0, a support base 21, an actuator for moving the support base 21 up and down, for example, a hydraulic cylinder 22, and a guide 23 for supporting the support base 21 so as to move up and down.
The guide 23 includes two guide bars 2 that support the support base 21.
7, 27 and guide holders 29, 29. The chuck 20 holds the journal portion 1a of the work 1 lightly so as not to wobble and supports the entire work. For example, in the case of the present embodiment, the fixed seat surface 24 fixed to the support base 21 and the actuator 25 that is installed opposite to the fixed seat surface 24 and presses the work 1 are used. 1 is provided so as to be held between the fixed seat surface 24 and the fixed seat surface 24. The actuator 25 is supplied with a working fluid, for example, pressurized air, through a flow passage 28 formed in the guide rod 27, and is provided so that the tightening of the chuck 20 can be released when the working pressure is applied. .. The guide rod 27 is slidably supported by a frame 19 of the direct transfer unit 10 via a guide holder 29. The chucks 20 and 20 are installed at the same intervals as the work pedestals 13 and 13 of the transfer unit 10.

The journal portion 1a of the work 1 lifted to the stroke end by the work holder 3 described above.
A centering clamp part 30 is constituted by a first centering member 5 for centering and a clamp part 7 for clamping the journal part 1a of the work 1.
The centering clamp portion 30 is incorporated in, for example, an NC servo motor or a hydraulic rotary actuator (not shown) and has a structure capable of rotating at an arbitrary angle while holding the work 1. Of course, the centering clamp portion 30 can be provided in an independent rotation mechanism separated from the NC servo motor of the processing machine. The first
The centering member 5 is provided with an air blow hole 32 for removing chips and the like generated by processing and the like. Further, the clamp portion 7 is composed of an actuating tube 31a surrounding the first centering member 5, a lever 31b engaging only with this in the axial direction, and a clamp piece 31c engaging with this lever 31b only in the radial direction. The linear movement of the actuating tube 31a in the axial direction is converted to the linear movement of the radial direction by the lever 31b to grip the journal portion 1a of the work 1.

On the other hand, the other second centering member 6 for centering the other end side of the work 1 and the pair of rotation direction guides 2, 2 are a rotation mechanism 33 and a second centering member for rotatably supporting them. The centering rotation positioning portion 4 is formed by the stopper 34 that prevents rotation of the rotation center 6 and the like.
6 are configured. A pair of rotation direction guides 2 and 2 for introducing the eccentric pin portion 1c of the work 1 for rough positioning in the rotation direction, and an axial positioning portion 4 for axially contacting the crank arm 1b in the axial direction. In the case of the present embodiment, are constituted by the same plate member. That is, the rotation direction guides 2 and 2 are composed of a pair of plates facing each other with an interval of the same width as the eccentric pin portion 1c,
At least one of the tip surfaces 4 is an axial positioning surface. In the case of the present embodiment, the second centering member 6 has a crank arm portion 37 with respect to a shaft portion 36 fitted and fixed to the rotary shaft 35 of the rotating mechanism 33, as shown in FIG.
It is fixed so as to be eccentric by a predetermined amount via, and a plurality of pieces corresponding to the eccentric amount of the eccentric pin portion 1c of the work 1 are prepared as necessary, and are replaceable and exchangeable as necessary. The rotation mechanism 33 includes the second centering member 6
And a rotary shaft 35 for supporting the rotary shaft 35, and an actuator 3 for supporting the rotary shaft 35 and the rotation direction guides 2 and 2 and moving the second centering member 6 in the axial direction between the rotary shaft 35 and the rotary shaft 35.
8 includes a cylinder portion 39, a spring 40 that constantly biases the rotating shaft 35 in a direction in which the second centering member 6 is separated from the work 1, and a bearing portion 41 that rotatably supports the cylinder portion 39. There is. The centering rotation positioning portion 46 includes a rotation stopping flat surface 37a of a crank arm portion 37 that supports the centering pin 6 that is the second centering member, and a rotation stopping pin 42 that projects from the bearing portion 41 toward the crank arm portion 37. And constitute a stopper 34. The rotation direction guides 2 and 2 and the second centering member 6 are fixed to the original position by the rotation stop pin 42 until the work 1 is clamped by the clamp portion 7 of the centering clamp portion 30. When the anti-rotation pin 42 is released, the rotation direction guides 2 and 2 and the centering pin 6 are rotatable and rotate together with the rotation of the centering clamp part 30. Reference numeral 45 is a position sensor for detecting the position of the rotation stop pin 42, that is, whether or not the second centering member 6 is fixed.

According to the positioning device constructed as described above, positioning is performed as follows. First, when the work 1 is sent to the processing station by the transfer unit 10, the chuck 20 of the work holder 3 is moved up to the work 1 by the action of the hydraulic cylinder 22 and temporarily stopped. Then, when the work 1 is chucked by the chuck 20, the work 1 starts to rise again. When the work 1 reaches the rising end, the first centering member 5 and the second centering member 6 move forward to move the center holes 1d and 1e at both ends of the work 1.
And the work 1 is positioned. At this time, since the work 1 is lightly held by the chuck 20, the horizontal and vertical inclinations of the work 1 are corrected and aligned. The positioning of the work 1 in the rotation direction is performed by the eccentric pin portion 1c of the work 1 being introduced between the pair of rotation direction guides 2 and 2 when the work 1 is lifted. Since it rotates by itself so as to fit between the two, positioning is performed to some extent in the rotation direction. The axial positioning of the work 1 is performed by pressing the work 1 against the end portions 4 of the rotation direction guides 2, 2. Therefore, the pressing force of the first centering member 5 is larger than that of the second centering member 6. Therefore, the work 1 is clamped by the clamp portion 7 of the centering clamp device 30 and the work holder 3 is lowered. Next, the anti-rotation pin 42 is pulled out to make the second centering member 6 and the rotation direction guides 2 and 2 rotatable, and the work 1 is rotated at an arbitrary angle by the NC servo motor or the hydraulic actuator to perform the predetermined processing of the work. I do. After the processing is completed, the operation reverse to the above is performed to return the processed work 1 to the work receiving portions 13 of the transfer portion 10 and send it to the next processing station, while the positioning and processing of the next work 1 and 1 are started. ..

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, two workpieces 1 and 1 are provided so as to be positioned and machined at the same time, but the invention is not particularly limited to this, and the workpieces are positioned one by one.
It may be processed.

[0017]

As is apparent from the above description, the positioning device of the present invention allows the eccentric pin portion of the work to move when the work is carried in between the first and second centering members that hold both ends of the work. It contacts the rotation direction guide and rotates around the journal, and after being positioned in the rotation direction to some extent, it is sandwiched by the first and second centering members to position the work in the vertical direction. Therefore, both centering members can be securely fitted into the center holes at both ends of the work to align them. Moreover, in this device, the axial positioning is performed by the axial positioning portion contacting the crank arm, and both ends of the work are held only by both centering members.
The work rotates about the centering member so that the center of gravity is located on the vertical line passing through the centering shaft, and the centering, the axial position, and the rotational position are determined. In this state,
Since the journal part is clamped, the work can be positioned at a fixed position.

Therefore, accurate positioning can be easily performed even for a crank-shaped work which has a small amount of eccentricity of the eccentric pin portion with respect to the journal portion and is difficult to obtain a proof for positioning.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a positioning device of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a diagram showing a rotation direction guide, (A) is a plan view,
(B) is a perspective view showing the relationship between the guide and the work.

FIG. 4 is a perspective view of a centering pin.

FIG. 5 is a partially sectional front view of a work holder part.

FIG. 6 is a side view of a work holder portion.

FIG. 7 is a front view of a direct transfer section.

FIG. 8 is a plan view of a direct transfer section.

FIG. 9 is a side view of a direct transfer section.

FIG. 10 is an explanatory diagram showing the principle of a conventional positioning device.

[Explanation of symbols]

 1 Work 1a Journal part 1b Crank arm 1c Eccentric pin part 2 Rotation direction guide 3 Work holder 4 Axial positioning part 5 First centering member 6 Second centering member 7 Clamp part

Claims (1)

[Claims] 1. A positioning device for positioning a work having a journal portion, a crank arm, and an eccentric pin portion eccentric with respect to the journal portion at a reference position for machining or the like, and an interval having substantially the same width as that of the eccentric pin portion. And a pair of rotation direction guides facing each other, and the relative movement between the rotation direction guides movably holds the journal portion of the workpiece by applying an external force to move the eccentric pin portion from the radial direction of the eccentric pin portion. A work holder introduced between the radial guide members; an axial positioning portion that axially contacts the crank arm of the work introduced between the rotation direction guides to axially position the work; The eccentric pin portion of the work introduced between the direction guides is fitted in the center holes respectively provided in the end surface of the eccentric pin portion and the end surface of the journal portion. First and second holding the work
Positioning device for a work having an eccentric part, which comprises a centering member and a clamp part for gripping the journal part when the work is released from the work holder and held by the both centering members. ..