JP2790928B2 - Work positioning device with eccentric part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for positioning a workpiece having an eccentric portion, for example, a crank-shaped workpiece. 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 to the journal portion at a reference position for processing or the like.

[0002]

2. Description of the Related Art Heretofore, in positioning a work having an eccentric portion such as a crankshaft, positioning is performed by using a portion having a small variation in dimensions of a crank arm as a proof for positioning. For example, as shown in FIG. 10, a stitch 105 parallel to the tangent of the journal 102 is provided along the journal 102 of the work 101, and the crank arm 103 is connected to the actuator 106
Press the like, it is pressed to rotate the crank arm 103 around the journal portion 10 2 to degrees per 105 so that positioning in a predetermined position. In this state, predetermined processing is performed by clamping the journal portion 102 and rotating the work 101 at a predetermined angle.

[0003]

However, according to this method, if the crank arm 103 of the work 101 is small and the eccentric pin 104 has a small amount of eccentricity, even if the crank arm 103 or the eccentric pin portion 104 is pushed by the actuator 106, this method is not possible. Since the generated rotational moment is smaller than the frictional force supporting the work, the work cannot be rotated around the work journal. Also,
Since the crank arm 103 has a large dimensional variation and cannot be used as a proof of rotation positioning, there is no portion other than the eccentric pin portion that is proof of rotation, and rotation positioning cannot be performed by the conventional method.

[0004] It is an object of the present invention to provide a positioning device for performing positioning in a rotational direction only by a journal portion and an eccentric pin portion even for a work having a small crank arm and a small eccentric amount.

[0005]

In order to achieve the above object, a work positioning device having an eccentric portion according to the present invention is provided.
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 opposed diacentric pin portions facing each other at substantially the same width. The journal portion of the work is movably held by the application of an external force by the relative movement between the rotation direction guide and the rotation direction guide, and the eccentric pin portion is moved from the radial direction of the eccentric pin portion to the pair of rotation direction guides. A work holder introduced between the rotating guides, an axial positioning portion that axially contacts the crank arm of the work introduced between the rotating guides to axially position the work, The end face and deviation of the journal of the work introduced into
First and second centering members which are fitted into respective center holes provided on the end surfaces of the core pin portions and hold the work, and the work is released from the work holder and held only by the centering members. Sometimes, it is constituted by a clamp portion which grips the journal portion.

[0006]

Therefore, if the work is held by the work holder in a state where the eccentric pin portion is displaced in the rotation direction, the width of the eccentric pin portion is substantially reduced when the eccentric pin portion is inserted between the rotation direction guides. It is regulated so that it fits inside, rotates around the journal part, and is positioned at a substantially constant position. That is, since the eccentric pin portion rotates around the journal by contacting the rotation direction guide, the positioning in the rotation direction is performed to some extent. Then, if the first and second centering members are fitted into 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 sandwiched by the first and second centering members and the shaft centers are aligned. At the same time, the work is rotated so that the center of gravity is located on a vertical 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 workpiece is also axially positioned by bringing the axial positioning portion into contact with the crank arm. In this state, if the journal is clamped, the work is positioned at a fixed position.

[0007]

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

FIGS. 1 to 9 show an embodiment in which a work positioning apparatus according to the present invention is implemented. This embodiment is an apparatus for performing a workpiece positioning clamp in preparation for processing at each processing station in a processing unit for sequentially transporting the work to a plurality of processing stations by a line type transfer and performing a series of processing.

This device comprises a pair of rotating 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 is rotatably held and lifted toward the rotation direction guides 2, 2, and the eccentric pin portion 1
The c and the work holder 3 to be introduced to the pair between the rotational direction guide 2, 2, from the axial direction to the crank arm 1b of the work 1 which is introduced between the rotating direction guide 2,2 abuts the axial direction of the workpiece Axial positioning part 4 for positioning and journal part of work 1 introduced between rotation direction guides 2
Center hole 1d on end face of 1a and end face of eccentric pin portion 1c
The work 1 is released from the work holder 3 and the work 1 is released from the work holder 3 and clamped only by the two centering members 5 and 6, and the rotation and axial positioning are completed. When the work 1 carried in by the direct transfer unit 10 is lifted while the journal unit 1a is lightly held by the work holder 3, the rotation direction guides 2, After the eccentric pin portion 1c is inserted into the shaft 2, positioning in the rotational direction is performed to a certain extent, and then the first and second centering members 5, 6 are sandwiched to perform axial positioning and rotational positioning again. I have.

As shown in FIG. 3B, the work 1 has a journal 1a, a crank arm 1b and a journal 1a.
This is a round part having an eccentric pin portion 1c eccentric with respect to. The center holes 1d and 1e are opened at the end surfaces of the journal portion 1a and the eccentric pin portion 1c.

The direct transfer unit 10 is shown in FIGS.
As shown in FIG. 9, transfer bars 12, 1 which are moved back and forth by an actuator, for example, a hydraulic cylinder 11.
2 and work receiving portions 13, 13 installed on the bars 12, 12 to support the work 1.
The workpieces 1, 1 are carried into the processing station by horizontally moving the workpieces 2, 12 by a predetermined amount. The transfer bars 12, 12 are slidably supported by 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 movement stroke of the transfer bar 12 on the way to the processing station, and the work 1 horizontally moved by a predetermined amount is once lifted from the work receiving portion 13. In the meantime, the transfer bar 12 is returned to the original position, and the work transfer means 14 is operated again to lower the work 1,
Another work receiving part 1 different from the one before lifting the work 1
3 is provided so that the work 1 is fed by a fixed amount at a time. The work receiving portion 13 is, for example, shown in FIG.
Has a U-shaped groove 15 for supporting the journal portion 1a of the work 1 as shown in FIG . In the case of the present embodiment, the direct transfer unit 10 transfers the two works 1 and 1 to the processing station simultaneously as a pair. Also,
The work transfer means 14 is composed of two sets of work receivers 16, 16 having the same shape as the work receiver 13, a gantry 17 for mounting the work receivers at predetermined intervals, and an actuator for supporting and raising and lowering the support, for example, a hydraulic cylinder 18. Become. Note that reference numeral 19 denotes a gantry.

The work holder 3 lifts the two works 1, 1 carried into the processing station by the direct transfer section 10 and transfers them between the first and second centering members 5, 6, and the work of the present invention. It constitutes a part of the positioning device. This work holder 3
Are chucks 20 and 2 that movably hold the work 1 lightly when an external force of a certain magnitude is applied, for example.
0, an actuator for elevating and lowering the support 21, for example, a hydraulic cylinder 22, and a guide 23 for supporting the support 21 up and down.
The guide 23 includes two guide rods 2 that support the support base 21.
7 and 27 and guide holders 29 and 29. The chuck 20 holds the journal portion 1a of the work 1 lightly so as not to move and supports the entire work. For example, in the case of the present embodiment, the work is constituted by a fixed seating surface 24 fixed to the support base 21 and an actuator 25 which is installed opposite to the fixed seating surface and presses the work 1. 1 is provided so as to be sandwiched between the fixed seat surface 24 and the fixed seat surface 24. A working fluid, for example, pressurized air is supplied to the actuator 25 via a flow passage 28 bored in the guide rod 27, and the actuator 25 is provided so that the tightening of the chuck 20 can be released when the working pressure is applied. . The guide bar 27 is slidably supported by the gantry 19 of the direct transfer unit 10 via a guide holder 29. Note that the chucks 20, 20 are installed at the same intervals as the work receiving tables 13, 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.
The centering clamp 30 is constituted by a first centering member 5 for centering the workpiece 1 and a clamp 7 for clamping the journal 1 a of the work 1.
The centering clamp unit 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 section 30 can be provided in an independent rotating mechanism separated from the NC servo motor or the like 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 or the like. The clamp portion 7 includes an operating tube 31a surrounding the first centering member 5, a lever 31b that engages only in the axial direction, and a clamp piece 31c that engages only with the lever 31b in the radial direction. The linear motion in the axial direction of the working tube 31a is converted into the linear motion in the radial direction by the lever 31b so as 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 and 2 are composed of a rotation mechanism 33 and a second centering member for rotatably supporting these. 6 and the stopper 34 for preventing rotation of the centering rotation positioning portion 4.
6 are constituted. 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 abutting the crank arm 1b in the axial direction to perform axial positioning. Are constituted by the same plate member in this embodiment. That is, the rotation direction guides 2 and 2 are constituted by a pair of plates facing each other at an interval of substantially the same width as the eccentric pin portion 1c,
At least one of the end surfaces 4 is an axial positioning surface. In the case of the present embodiment, the second centering member 6 is, as shown in FIG. 4, a crank arm 37 with respect to a shaft 36 fitted and fixed to a rotating shaft 35 of a rotating mechanism 33.
The work 1 is fixed so as to be eccentric by a predetermined amount, and a plurality of eccentric pins 1c of the work 1 corresponding to the amount of eccentricity are prepared as necessary, and are provided so as to be replaceable and exchangeable as needed. The rotation mechanism 33 includes the second centering member 6.
And an actuator 3 that supports the rotation shaft 35 and the rotation direction guides 2 and 2 and moves the second centering member 6 in the axial direction between the rotation shaft 35 and the rotation shaft 35.
8, 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 41 that rotatably supports the cylinder 39. I have. The centering rotation positioning portion 46 includes a detent plane 37a of the crank arm portion 37 supporting the centering pin 6 as a second centering member and a detent pin 42 projecting from the bearing portion 41 toward the crank arm portion 37. Constitutes a stopper 34. Until the work 1 is clamped by the clamp portion 7 of the centering clamp portion 30, the rotation direction guides 2 and 2 and the second centering member 6 are fixed at the original positions by the rotation preventing pins 42 so as not to rotate. When the rotation preventing pin 42 is released, the rotation direction guides 2 and 2 and the centering pin 6 become rotatable, and rotate together with the rotation of the centering clamp unit 30. Reference numeral 45 denotes a position sensor for detecting the position of the rotation preventing pin 42, that is, whether or not the second centering member 6 is fixed.

According to the positioning device configured 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 moves up to the work 1 by the action of the hydraulic cylinder 22 and temporarily stops. Then, when the workpiece 1 is chucked by the chuck 20, the ascent starts again. When the work 1 reaches the rising end, the first centering member 5 and the second centering member 6 move forward and the center holes 1d, 1e at both ends of the work 1.
And the work 1 is positioned. At this time, since the work 1 is held lightly 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 such that when the work 1 is lifted, the eccentric pin 1c of the work 1 is introduced between the pair of rotation guides 2 and 2 so that the eccentric pin 1c is rotated by the rotation guides 2 and 2. Since it rotates by itself so that it fits between the two, positioning in a certain rotational direction is performed. The positioning of the work 1 in the axial direction is performed by pressing the work 1 against the end portions 4 of the rotation direction guides 2 and 2. For this reason, the pressing force of the first centering member 5 is pressed with a larger force than 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 detent pin 42 is removed to make the second centering member 6 and the rotation direction guides 2 and 2 rotatable, and the work 1 is rotated to an arbitrary angle by an NC servomotor or a hydraulic actuator to perform predetermined processing of the work. I do. After the processing, the operation opposite to the above is performed to return the processed work 1 to the work receiving sections 13 and 13 of the transfer section 10 and send it to the next processing station, while starting the positioning and processing of the next work 1 and 1. .

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

[0017]

As is apparent from the above description, in the positioning device of the present invention, the eccentric pin portion of the work is used when the work is carried in between the first and second centering members for holding both ends of the work. After rotating around the journal in contact with the rotation direction guide, and after being positioned to some extent in the rotation direction, it is sandwiched between the first and second centering members so as to be positioned vertically with respect to the axis of the work. Therefore, the centering members can be securely fitted into the center holes at both ends of the work and aligned. In addition, in this device, the axial positioning is performed by contacting the axial positioning portion with the crank arm, and both ends of the work are clamped only by the two centering members.
The work rotates around the centering member so that the center of gravity is located on a perpendicular line passing through the centering axis, and the alignment, the axial position, and the rotational position are determined. In this state,
Since the journal is clamped, the work can be positioned at a fixed position.

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

[Brief description of the drawings]

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

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

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

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

FIG. 5 is a partial cross-sectional front view of a work holder part.

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

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

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

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

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

[Explanation of symbols]

 DESCRIPTION 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)

(57) [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, wherein an interval having substantially the same width as the eccentric pin portion is provided. A pair of rotation direction guides facing each other, and the relative movement between the rotation direction guide holds the journal portion of the work so as to be movable by applying an external force, and holds the eccentric pin portion from the radial direction of the eccentric pin portion. a work holder to be introduced into between a pair of rotating direction guide, and axial positioning portion in which the direction of rotation to the guide crank arm of the work that has been introduced between the axially abuts for positioning the axial direction of the workpiece, Journal of the workpiece introduced between the rotating direction guides
A first and a second centering member for clamping respectively fitted into by the workpiece end face and the end face of the eccentric pin portion parts respectively center hole provided by the two centering members is released the workpiece from the workpiece holder A work positioning device having an eccentric portion, comprising a clamp portion for gripping the journal portion only when the journal portion is held.