JP4529947B2 - Workpiece support device and workpiece processing method - Google Patents

Description

  The present invention relates to a workpiece support device and a workpiece processing method, and is applied to a workpiece support device and a workpiece processing method for processing a fuel injection nozzle that injects fuel into a combustion chamber of an engine. And suitable.

  FIG. 4 shows a cross-sectional view of a state in which a conventional injection nozzle is attached and fixed to a conventional workpiece support means 100. V is a conventional fuel injection nozzle which is a workpiece. Since the accuracy of the injection hole V9 disposed in the fuel injection nozzle V directly affects engine combustion, a very high level is required. This accuracy is, for example, an offset amount (indicated by S in FIG. 3) with respect to the center line Va of the nozzle body V, a degree of symmetry (not shown), and the like.

  By the way, the conventional fuel injection nozzle V (workpiece) has a sufficient nozzle length H0. For this reason, using the first female taper portion V1 and the female guide portion V2 of the nozzle V, the first male taper portion 90a and the male guide portion 90b of the workpiece support means 90 are brought into contact with or guided by these, The nozzle V was pressed in the direction of the arrow by the pressing plate 91 and fixed to the main body 92 to process the nozzle hole V9.

  The workpiece support means 90 is also a machining reference, and is connected to a driving means for displacing to a desired position in the plane coordinates XY with respect to an electric discharge machine (not shown) as the machining means. The above-described nozzle hole accuracy is ensured by attaching the workpiece V to the workpiece support means 90, which is the machining reference, with the gap kept in a minimum contact.

  However, a gap (hereinafter referred to as “guide gap”) exists between the female guide portion V2 of the workpiece V and the male guide portion 90b of the workpiece support means 90. For this reason, the center line Va of the workpiece V (corresponding to Wa in FIG. 3) has a slight inclination (hereinafter referred to as “workpiece inclination”) with respect to the center line 90x of the workpiece support means 90. Will have. This workpiece inclination rate adversely affects the machining accuracy of the nozzle hole V9. Further, the workpiece inclination rate is substantially proportional to H1 / H2 shown in FIG. 4 if the guide gap is constant. For this reason, the conventional nozzle has adopted a dimension in which H1 / H2 becomes sufficiently small by increasing the nozzle length H0. H1 is the distance between the workpiece tip and the first contact point, and H2 is the distance between the first contact point and the guide center point.

  On the other hand, the demand for reducing the engine volume continues, and the new nozzle W having a reduced nozzle length H0 is employed in the new engine to satisfy this demand. This new nozzle W is shown in FIG. In this case, since it is difficult to reduce H1, it is decided to reduce H2 by reducing H2. This means that the inclination rate deteriorates and the nozzle hole accuracy is not ensured.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a workpiece support means for accurately processing the nozzle hole of a fuel injection nozzle having a small nozzle length and a method of using the same. It is.

As means for solving the above-mentioned problems, the present invention provides a workpiece support means and a method of using the same according to the claims.
According to the first aspect of the present invention, the workpiece support means includes first support means having a first male taper portion that abuts on the first female taper portion of the workpiece, and a second support of the workpiece. Second support means having a second male taper part that contacts the female taper part, wherein the first support means and the second support means are slidable with respect to each other, and the workpiece (W ) Is a fuel injection nozzle, which is used when machining the nozzle hole of the fuel injection nozzle . Since the two places supporting the workpiece are both tapered, there is no gap and positioning can be performed. For this reason, the workpiece inclination does not occur theoretically. The nozzle hole accuracy mainly depends only on the accuracy of the female taper of the nozzle. (This is because the same workpiece support means is always used.) This makes it possible to accurately process the nozzle hole of the fuel injection nozzle having a small nozzle length.

  According to the invention described in claim 2, the workpiece support means is characterized in that the first male taper portion or the second male taper portion has a two-step taper. The contact portion between the first-stage female taper and the second-stage male taper is not a surface contact but a line contact. For this reason, it becomes possible to position stably and accurately.

  According to invention of Claim 3, the processing method processes the said workpiece using the workpiece support means of Claim 1 or 2, It is characterized by the above-mentioned.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a state immediately before the new workpiece (fuel injection nozzle) is attached and fixed to the workpiece support means of the present invention. FIG. 2 is a cross-sectional view of a state in which a new workpiece is attached and fixed to the workpiece support means of the present invention. FIG. 3 is a cross-sectional view of the new workpiece.

  In FIG. 1, reference numeral 10 denotes a workpiece support means, 1 denotes a first support means, 1a denotes a first male taper portion, 2 denotes a second support means, 2a denotes a second male taper portion, and W denotes a workpiece (fuel). Spray nozzle), W1 is a first female taper portion, W2 is a second female taper portion, W3 is a nozzle hole (actually, no nozzle hole is formed at this stage), 3 biases the second support means 2 A spring 4 for attaching and fixing the workpiece W to the workpiece W 4, a pressing plate for abutting and fixing the workpiece W to the second support means 2, and a box 5 for accommodating the spring 3.

  As shown in FIG. 2, in a state where the workpiece W is attached and fixed, the first male taper portion 1a of the first support means 1 comes into contact with the first female taper portion W1 of the workpiece W and is first. The second male tapered portion 2a of the second supporting means 2 is in contact with the second female tapered portion W2 of the workpiece W to constitute the second supporting position. The 1st male taper part 1a is comprised from the 1st step taper part 1b and the 2nd step taper part 1c, and is a 2 step | paragraph taper.

  When the first female taper angle is θw1 (see FIG. 1), the first step taper angle is θ1b, and the second step taper angle is θ1c, each taper angle is such that θ1c <θw1 <θ1b. It is configured. Each angle difference between θw1 and θ1b and θ1c is extremely small, for example, about 0.5 °. Since the first male taper portion 1a has a two-step taper, the contact with the counterpart first female taper portion W1 is not a surface contact but a line 1d (the first step taper portion 1b and the second step taper). Line contact occurs at the boundary line with the portion 1c. By this line contact, the positioning of the first female taper portion and the first male taper portion becomes stable and accurate.

  The mutual relationship between the second female taper portion W2 and the second male taper portion 2a is the same as the mutual relationship between the first female taper portion W1 and the first male taper portion 1a. It becomes. Since the function and effect are the same as those described above, description thereof is omitted. The conventional second support position is configured by the sliding guide portions V2 and 90b as shown in FIG. For this reason, due to the presence of the clearance between the sliding guide portions, the workpiece may be inclined with respect to the support means 90, and it has been difficult to accurately process the nozzle hole of the long full length H0. However, in the embodiment of the present invention, since the portion is tapered instead of the sliding guide portion, there is no gap and positioning error (nozzle inclination) is eliminated.

  On the other hand, the first support means 1 and the second support means 2 are slidable with respect to each other. The gap between the first support means 1 and the second support means 2 is extremely small, for example, 1 to 2 μm. By making it slidable, it becomes easy to attach and fix the workpiece W to the support means 10.

  Next, a method for attaching the workpiece W to the workpiece support means 10 will be described. As shown in FIG. 1, first, the nozzle (workpiece W) is placed on the assembly of the first support means 1 and the second support means 2, the spring 3, and the box 5 (that is, the work piece support means 10). Install. Thereafter, the pressing plate 4 is brought into contact with the shoulder W4 of the workpiece W. In this state, the first female taper portion W1 of the workpiece W and the first male taper portion 1a of the first support means 1 are not in contact with each other.

  When the push plate 4 is pushed down in the direction of the arrow (downward) in FIG. 2, the first female taper portion W1 of the workpiece W and the first male taper portion 1a of the first support means 1 come into contact. Then, the workpiece W cannot be lowered in the direction of the arrow any more. In this state, the push plate 4 is fastened and fixed by fastening and fixing means (not shown).

  At this stage, the process of attaching the workpiece W to the workpiece support means 10 ends. In the next step, the nozzle hole W3 is opened at the tip of the workpiece W by an electric discharge machine.

  As described above, in the present invention, it is possible to obtain a workpiece support means and a method for using the same for processing a fuel injection nozzle hole having a small nozzle length with high accuracy.

It is sectional drawing of the state just before attaching and fixing a new type workpiece to the workpiece support means of this invention. It is sectional drawing of the state which attached and fixed the new type workpiece to the workpiece support means of this invention. It is sectional drawing of a new type workpiece. It is sectional drawing of the state which attached and fixed the conventional workpiece to the conventional workpiece support means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st support means 2 2nd support means 10 Workpiece support means W Workpiece

Claims (3)

First support means (1) having a first male taper portion (1a) that contacts the first female taper portion (W1) of the workpiece (W);
Second support means (2) having a second male taper portion (2a) in contact with the second female taper portion (W2) of the workpiece (W),
The first support means (1) and the second support means (2) are slidable with respect to each other ;
A workpiece support means (10) , wherein the workpiece (W) is a fuel injection nozzle, and is used when processing a nozzle hole of the fuel injection nozzle .   The workpiece according to claim 1, wherein the first male taper portion (1a) or the second male taper portion (2a) is a two-step taper (1b, 1c; 2b, 2c). Support device.   A processing method for processing the workpiece using the workpiece support device according to claim 1.

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