JP2005186208A - Machining tool and work machining method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform machining without holding a work part by part unlike the conventional rack guide of a steering mechanism in which part of the outer periphery of a work is held to machine the outer periphery of a non-holding part, and subsequently, the work is shifted to machine the outer periphery of the previously held part. <P>SOLUTION: A fitting part 2 corresponding to a guide part for the work is provided with a projecting part 5 for positioning in the direction of X-axis and a projecting part 4 for positioning in the direction of Y-axis, which are engaged with the recessed parts formed on the guide part, and further a holding part 7 of a finishing machine is provided to constitute a machining tool 1. The work is pressed in the direction of Z-axis by the inclined side surfaces 4a, 4a and 5a, 5a of the machining tool 1 to be held in a space up to the center of the finishing machine, and rotation is transmitted to the work through the machining tool 1 held by the finishing machine to machine the outer periphery of the work. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a machining jig that enables efficient and accurate machining of the outer periphery of a work without changing the work, and a work machining method using the jig.

  One of the gear mechanisms employed in the steering mechanism of an automobile is a rack and pinion type gear mechanism. This rack and pinion type gear mechanism meshes the rack with a pinion connected to the steering shaft, and transmits the movement of the handle to the tire via the pinion and the rack.

  The rack is supported by a rack guide incorporated in the gear case. An example of the rack guide is shown in FIGS.

  The rack guide 20 is biased toward the pinion side by a spring and incorporated in the gear case, and a rack meshed with the pinion is fitted into a concave semi-cylindrical guide portion 21 to guide the movement of the rack. In the illustrated rack guide, a concave portion 22 (groove) having a cross-sectional view in the end surface is formed in the guide portion 21, and a resin (not shown) having a small friction coefficient is fitted into the concave portion 22, and the rack is supported by the resin when the rack is moved. The frictional resistance is reduced.

  The rack guide 20 is made of a forged product, a cast product, and a sintered product manufactured by the powder metallurgy method, so that the outer diameter accuracy is increased to eliminate the rattling of the handle, and the ratchet in the gear case is reduced. It is required to suppress.

  In order to meet the demand, the outer periphery of the rack guide 20 is machined, but when the outer periphery is processed by holding a part of the rack guide 20 with a holder, for example, a chuck, mounted on the spindle of the processing machine, the chuck is gripped with the chuck. The part cannot be processed. For this reason, after processing a part of outer periphery, the processed part and the unprocessed part were replaced | exchanged (work is changed), and the method of processing the remaining unprocessed part had to be taken.

  In the above-described machining method, it is necessary to change the workpiece, and the machining efficiency does not increase. Moreover, since the processed surface is gripped by the chuck when the unprocessed portion is processed, the processed surface may be damaged.

  Therefore, an object of the present invention is to provide a machining jig that enables machining without changing the rack guide and the like, and a workpiece machining method using the jig.

  In order to solve the above-described problems, in the present invention, a convex portion or concave portion for positioning in the X-axis direction and a Y-axis direction positioning that are engaged with the concave portion or convex portion at one end of the workpiece on the orthogonal X, Y, and Z axes. For the Z-axis direction in a direction in which the opposing side surfaces of the convex or concave portions for positioning in the X-axis direction and for positioning in the Y-axis direction are opposite to each other. Provided is a machining jig that is inclined and positioned at a machining center parallel to the Z axis by pressing the workpiece in the Z axis direction with the inclined side surface of the convex or concave portion.

  The X axis and the Y axis mentioned here are axes that intersect at right angles (for example, when the X axis is a horizontal axis, the Y axis is a vertical axis), and the Z axis is an axis that is perpendicular to both the X axis and the Y axis. .

As this machining jig, the following (1) and (2) are considered as preferable forms.
(1) A surface corresponding to the one end of the workpiece is configured by a curved surface or a spherical surface, and the convex portion or concave portion for positioning in the X-axis direction and the convex portion or concave portion for positioning in the Y-axis direction are provided on the curved surface or spherical surface. What is being done.
(2) The convex portion or concave portion for positioning in the X-axis direction and the convex portion or concave portion for positioning in the Y-axis direction intersect at the center of the jig, and extend to the outer periphery of the jig across the center of the jig. .

  In the present invention, the above-mentioned machining jig is held at the machining center by a holder mounted on the spindle of the processing machine, and the convex or concave portions for positioning in the X-axis direction and Y-axis direction of the machining jig are provided. Engage with the recess or projection on the end face of the workpiece, and press the workpiece in the Z-axis direction with the side surface inclined with respect to the Z-axis direction of the projection or recess for positioning in the X-axis direction and Y-axis direction. The workpiece is sandwiched between the machining jig and the center of the processing machine, and the workpiece positioned at the machining center is rotated by the force transmitted via the machining jig to machine the outer periphery of the workpiece. A workpiece machining method is also provided.

  The machining jig according to the present invention is set on a processing machine by holding a holding portion provided on the jig with a chuck or the like attached to the spindle of the processing machine.

  Then, the workpiece is pushed in the Z-axis direction on the side surface of the convex portion or concave portion for positioning in the X-axis direction and the convex portion or concave portion for positioning in the Y-axis direction provided in the machining jig, and the machining jig and the processing machine Between the center. The side surface of the convex portion or concave portion that pushes the workpiece is provided inclined with respect to the Z-axis direction. In the case of a convex part, the side surface is inclined so that the tip side is narrow with respect to the work and the width becomes wider toward the base of the convex part of the machining jig. It is wide and inclined so as to narrow toward the bottom of the concave groove. The workpiece pushed to this side is centered by the component force acting on the contact part with the side, and the positional deviation in both the X-axis and Y-axis directions is automatically corrected and correctly positioned and held at the machining center. Easy to set.

  In this state, the convex or concave portion on the machining jig side engages with the concave or convex portion on one end of the workpiece, and the rotation applied to the machining jig from the spindle of the processing machine is transmitted to the workpiece and the workpiece also rotates. .

  Therefore, if the machining jig of the present invention is used, it is not necessary to directly grip the workpiece with a processing machine, and the entire outer periphery of the workpiece can be machined without changing the workpiece.

  A machining jig provided with a convex or concave portion for positioning in the X-axis direction and the Y-axis direction on a curved surface or a spherical surface is a workpiece whose one end is a curved surface or a spherical surface, such as the rack guide of FIG. Enables machining without changing the machine.

  Also, the projection or recess for positioning in the X-axis direction and the projection or recess for positioning in the Y-axis direction intersect at the center of the jig and extend across the center of the jig to the outer periphery of the jig. The stability of the workpiece positioning is further increased.

  Embodiments of a machining jig according to the present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings. The illustrated machining jig 1 is used for machining the rack guide 20 shown in FIG. The following description will be given with reference to FIGS.

  This machining jig 1 is provided with a fitting portion 2 that fits and fits into the semicylindrical guide portion 21 of the rack guide 20 shown in FIGS. 7 and 8, and the fitting portion 2 of FIG. Protrusions 4 and 5 that intersect at right angles at the center of the jig are provided on the convex curved surface 3 that draws a circle. Further, a hook 6 is provided at the rear part of the fitting part 2, and further, a holding part (that is a handle in the figure) 7 is provided behind the hook 6 to be held by a holder of the processing machine.

  The convex part 4 is provided in the part used as the edge of the front-end | tip of the fitting part 2. FIG. The convex portion 4 linearly extending in the X-axis direction from the center of the convex curved surface 3 (center of the jig) toward the outer periphery of the fitting portion 2 is used for positioning the rack guide 20 of the workpiece in the Y-axis direction. Used for.

  Further, the convex portion 5 extending in the Y-axis direction from the center of the convex curved surface 3 to the outer periphery of the fitting portion 2 while being displaced in the Z-axis direction along the curved surface positions the rack guide 20 in the X-axis direction. Used for.

  The side surfaces 4a, 4a and 5a, 5a at the opposing positions of these convex portions 4, 5 are inclined in opposite directions, that is, in a direction in which the cross section of each convex portion 4, 5 is trapezoidal, 5 is inserted into the recess 22 (groove) provided in the rack guide 20, and the side surfaces 4a, 4a and 5a, 5a push the inclined side surface of the recess 22 in the Z-axis direction to position the rack guide 20 at the processing center of the processing machine. Like to do.

  Since the side surfaces 4a and 5a are both inclined, a component force in the Y-axis direction is generated at the contact portion of the side surface 4a with the rack guide 20, and a component force in the X-axis direction is generated at the contact portion of the side surface 5a. The component forces at this time are the forces acting on the side surfaces 4a and 4a and the forces acting on the side surfaces 5a and 5a, respectively. Therefore, the rack guide 20 has a balance between the component forces acting on the side surfaces 4a and 4a and the side surface 5a. 5a is moved to the balance point of the component force acting on 5a, whereby the positional deviation in the X-axis direction and the Y-axis direction is corrected, and the rack guide 20 is correctly positioned at the processing center.

  Here, for convenience, the convex portion 4 is used for positioning in the Y-axis direction and the convex portion 5 is used for positioning in the X-axis direction. However, when the machining jig 1 is rotated 90 ° from the state shown in FIG. Is positioned by the convex portion 4 and positioning in the Y-axis direction is performed by the convex portion 5.

  The illustrated convex portions 4 and 5 are elongated strips, but may not be strip-shaped depending on the shape of the concave portion formed on the end surface of the workpiece.

  Further, when there is no recess on the end surface of the workpiece and a convex portion is formed in place of the concave portion, a concave portion corresponding to the convex portion is provided in the fitting portion 2 instead of the convex portions 4 and 5 in the figure. .

  Furthermore, here, the fitting portion 2 is curved in a convex shape so as to correspond to the guide portion 21 of the rack guide, but the end surface of the work that abuts the fitting portion 2 is a convex curved surface or a convex spherical surface. For this, the fitting portion 2 is preferably a concave curved surface or a concave spherical surface.

  FIG. 5 shows a specific example of a workpiece (rack guide) machining method using the illustrated machining jig 1. In the figure, reference numeral 10 denotes a holder (for example, a chuck) mounted on a spindle (not shown) of the processing machine. The holder 10 is held by the holder 10 and the machining jig 1 is set on the processing machine.

  Next, as shown in FIG. 6, the convex portions 4 and 5 provided in the fitting portion 2 enter the concave portion 22 formed in the guide portion 21, and the fitting portion 2 of the machining jig 1 is racked. Fit into the guide portion 21 of the guide 20.

  Then, the rack guide 20 is sandwiched between the center 11 (tail end) of the processing machine and the machining jig 1. At this time, the rack guide 20 is pushed in the Z-axis direction as shown in FIG. 6 by the side surfaces 4a and 5a of the convex portions 4 and 5. Thereby, the rack guide 20 is centered and fixed to the processing center.

  Therefore, the processing machine is driven and the rack guide 20 is rotated by the rotational force transmitted from the main shaft via the machining jig 1 to machine the outer periphery of the rack guide 20.

  In addition to turning with the cutting tool 12, machining, grinding, polishing, and the like are also conceivable. Both processes are performed by feeding a machining tool such as a cutting tool in the Z-axis direction. According to this method, the entire outer peripheral surface of the rack guide 20 can be processed efficiently without changing the rack guide 20.

  Further, since it is not necessary to change the rack guide, the processed surface is not damaged by a chuck or the like.

  In addition, although the above description gave and demonstrated the rack guide as an example, the jig | tool and processing method of this invention are not limited to what was intended for the rack guide.

The perspective view which shows an example of the machining jig of this invention Side view of the machining jig of FIG. 1 is a side view of the machining jig shown in FIG. Front view of the machining jig of FIG. The diagram which shows an example of the workpiece processing method using the machining jig of FIG. The figure which shows the state pressed against the workpiece recessed part of the side surface of a convex part Rack guide perspective view Sectional view of the rack guide of FIG. Front view of the rack guide of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Machining jig 2 Fitting part 3 Convex curved surface 4 Convex part 4a Side surface 5 Convex part 5a Side surface 6 鍔 7 Holding part 10 Holding tool 11 Center 12 Bit 20 Rack guide 21 Guide part 22 Concave part

Claims (4)

  A convex part or concave part for positioning in the X-axis direction and a convex part or concave part for positioning in the Y-axis direction to be engaged with the concave part or convex part at one end of the workpiece on the three axes orthogonal to each other, the X axis, the Y axis, and the Z axis; A holding portion by a processing machine, and the convex or concave portions for positioning in the X-axis direction and the Y-axis direction are inclined with respect to the Z-axis direction in opposite directions. Machining jig in which the workpiece to be machined on the slanted side is pressed in the Z-axis direction and positioned at the machining center.   A surface corresponding to the one end of the workpiece is formed by a curved surface or a spherical surface, and the convex portion or concave portion for positioning in the X-axis direction and the convex portion or concave portion for positioning in the Y-axis direction are provided on the curved surface or spherical surface. The machining jig according to claim 1.   The projection or recess for positioning in the X-axis direction and the projection or recess for positioning in the Y-axis direction intersect at the center of the jig and extend to the outer periphery of the jig across the center of the jig. 2. The machining jig according to 2.   The machining jig according to any one of claims 1 to 3 is held at a machining center by a holder mounted on a spindle of a processing machine, and is used for positioning in the X-axis direction and positioning in the Y-axis direction of the machining jig. The protrusion or recess is engaged with the recess or protrusion on the end face of the workpiece, and the workpiece is pushed in the Z-axis direction by the inclined side surface of the protrusion or recess for positioning in the X-axis direction and positioning in the Y-axis direction. The workpiece is machined on the outer periphery of the workpiece by sandwiching the workpiece between the machining jig and the center of the machining machine and rotating the workpiece positioned and held at the machining center with the force transmitted via the machining jig. Processing method.

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