JP2017104935A - Clamp jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamp jig that is able to prevent damage to a seat surface of a pressed powder molding processed before sintered, and is used for clamping the pressed powder molding.SOLUTION: A clamp jig 20 according to an embodiment comprises: a rotary member 21 supported by a rotary shaft 22 so as to freely rotate and a pair of first clamp arm 23a and second clamp arm 23b attached to the rotary member 21 with the rotary shaft 22 between them, abutting on a work 10 so as to sandwich a thin wall part formed in the pressure work 10 during seat surface processing, and clamping reference metals 103 with the reference metals 103.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a clamp jig.

  Conventionally, the powder metallurgy method is known as one of the manufacturing methods of a machine part. In the powder metallurgy method, a metal powder is placed in a mold and a pressure compact is formed by applying pressure, and a mechanical part having a predetermined shape is manufactured by subjecting the powder compact to a sintering treatment.

  In a machine part, a shape that is difficult to be molded by a mold is formed by machining. However, since the sintered product has high hardness, it is very difficult to perform machining such as cutting after the sintering process. Thus, Patent Document 1 proposes a method for manufacturing a sintered product, in which a green compact before the sintering treatment is subjected to machining, so-called green processing.

JP2013-053353A

  In green processing, since the cutting resistance of the green compact is small, processing can be performed in a short time. However, since the green compact before the sintering treatment has a low strength and is very brittle, there is a problem that cracks and chips are likely to occur.

  The present inventor, in particular, when a thin-walled portion (hereinafter referred to as a thin-walled portion) is formed in the step of performing a seating surface processing on a green compact before sintering, the cutting force during the seating surface processing is As a result, it was found that cracks and cracks easily occur in this part and other stress concentration parts. In the step of applying a seating surface to the compacted body, the seating surface processing is performed in a state where the compacted body placed on the reference metal is clamped at one point by the clamping jig while avoiding the thin portion. Is called. For this reason, the green compact before sintering is greatly affected by bending force applied to the green compact during clamping due to cutting force during machining and undulation of the clamp surface of the green compact. It becomes.

  The present invention has been made against the background of the problems as described above, and the object of the present invention is to reduce the pressure during the seating process of the green compact before sintering. It is to provide a clamping jig for clamping a powder molded body.

  The clamp jig according to the embodiment is a clamp jig that clamps the green compact when the seat compact is placed on the green compact before sintering that is placed on the reference metal. A rotating member that is rotatably supported by the rotating shaft, and the rotating member that is attached to the rotating member with the rotating shaft interposed therebetween, and that the thin portion formed in the compacting body is sandwiched during the seating surface processing. Each is provided with a pair of clamp arms that abut against the green compact and clamp the green compact with the reference metal.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the clamp jig | tool which clamps the said compacting body which can prevent the damage at the time of the seating surface processing of the compacting body before sintering. .

It is a schematic diagram which shows the structure of the processing apparatus which concerns on embodiment. It is a figure explaining the structure of the clamp jig | tool used for the processing apparatus of embodiment. It is a figure explaining the structure of the clamp jig | tool seen from the arrow A of FIG. It is a figure explaining attraction blow used for the processing apparatus of an embodiment. It is a figure explaining the end mill holder used for the processing apparatus of an embodiment. It is a perspective view which shows the structure of a workpiece | work. It is a figure explaining the state by which a seat surface process is given to the workpiece | work of a comparative example. In the comparative example, when forming the seating surface processing part on the workpiece placed on the reference gold, each protruding portion is clamped at one point with the reference gold by the clamp jig. FIG. It is a figure explaining the state by which a seat surface process is given to a workpiece | work in the clamped state of FIG. It is a figure explaining the state which collect | recovers the chips scattered at the time of the seat surface process of FIG. 9 with a dust collector.

  Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, components having the same action are denoted by the same reference numerals. In addition, the dimensional relationship in each figure does not reflect the actual dimensional relationship.

  The embodiment is used in a processing apparatus that performs machining, so-called green processing, on a green compact (hereinafter referred to as a workpiece) before sintering, and clamps and holds the workpiece during machining. About.

  First, with reference to FIG. 6, the structure of the workpiece | work 10 which is machined with the processing apparatus which concerns on embodiment is demonstrated. FIG. 6 is a perspective view showing the configuration of the workpiece 10. The workpiece 10 is a green compact before sintering, which is formed by putting metal powder into a mold and applying pressure. As shown in FIG. 6, four projecting portions 11 are formed on the disk-shaped workpiece 10 as viewed from above. The four protruding portions 11 are arranged at equal intervals on one surface side of the disk-shaped workpiece 10.

  A seating surface processing portion 12 is formed on each of the upper surfaces of the four projecting portions 11. That is, in the embodiment, the seat surface processing is performed as the green processing, and the seat surface processing portion 12 is formed on the workpiece 10. A machining remaining portion 13 is formed at a position along the outer periphery of the workpiece 10 in the seating surface machining portion 12. The processing remaining portion 13 is formed so as to gradually become thinner from the surface where the protruding portions 11 face each other toward the central portion along the outer periphery of the protruding portion 11. For this reason, the center part of the processing remaining part 13 becomes the thin part 14 with the smallest thickness.

  Here, before describing the clamp jig according to the embodiment, a comparative example will be described with reference to FIGS. FIG. 7 is a diagram for explaining a state in which a seating surface process is performed on the workpiece 10 according to a comparative example. FIG. 8 is a view of the workpiece 10 as seen from the surface side on which the four protrusions 11 are formed. FIG. 8 shows that, in the comparative example, when forming the seating surface processing portion 12 on the workpiece 10 placed on the reference gold, each protruding portion 11 is connected to the reference gold by a clamp jig at one point. The clamped state is shown.

  FIG. 9 is a diagram for explaining a state in which a seating surface process is performed on the workpiece in the clamped state of FIG. FIG. 9 shows the positional relationship between the workpiece 10, the end mill 1, and the clamp arm 2 from the side surface perpendicular to the workpiece 10 of the protruding portion 11.

  As shown in FIG. 9, the workpiece 10 is placed on the reference gold 3. As shown in FIG. 8, one projecting portion 11 of the workpiece 10 is fixed to the reference metal 3 by the clamp arm 2 while avoiding the thin portion 14 on the upper surface of the processing remaining portion 13. That is, one protrusion is fixed at one point where the clamp arm 2 contacts. The workpiece 10 is fixed between the reference metal 3 and the four clamp arms 2. The upper surface of the processing remaining portion 13 becomes a clamp surface.

  Since the thin portion 14 is formed at the center along the outer periphery of each protrusion 11, the contact position of the clamp arm 2 is shifted from the center of the protrusion 11. As shown in FIG. 9, the workpiece 10 is subjected to seating processing by the end mill 1 in the clamped state of FIG. 8, and a seating surface processing portion 12 is formed on the protruding portion 11. When the bearing surface is processed by the end mill 1, a cutting force is generated.

  As described above, the contact position of the clamp arm 2 of the workpiece 10 is shifted from the central portion of the protrusion 11, and the workpiece 10 is clamped by the influence of the mounting surface of the reference metal 3 and the undulation of the clamp surface of the workpiece 10. When it is done, the work 10 may be bent. Moreover, the workpiece | work 10 before a sintering process receives to the influence of the cutting force by an end mill at the time of a seat surface process. Due to such waviness of the clamp surface and cutting load, cracks and cracks are likely to occur particularly in the thin portion 14.

  Further, FIG. 10 shows a state where the dust that is scattered when the workpiece 10 is seated as shown in FIG. 7 is collected by the dust collector 4. As shown in FIG. 10, in the seat surface processing by the end mill 1, chips (iron powder) of 0.1 mm or less are scattered. As shown in FIG. 10, in the open space, when the suction port of the dust collector 4 is arranged near the processing site to collect the chips, the chip collection rate is as low as 60%, and the chips are in the facility. There is also a problem that the working environment / movability deteriorates due to diffusion and accumulation around the processing apparatus.

  In the embodiment, a clamp jig capable of preventing damage at the time of processing the seating surface of the workpiece 10 before the sintering process is provided. Further, an example of efficiently collecting scattered chips in a processing apparatus using such a clamp jig will be described.

  A processing apparatus using a clamp jig according to an embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a processing apparatus 100 according to an embodiment. FIG. 2 is a diagram illustrating the configuration of the clamp jig 20 used in the processing apparatus 100. FIG. 3 is a diagram illustrating the configuration of the clamping jig 20 as viewed from the arrow A in FIG.

  As shown in FIG. 1, the processing apparatus 100 includes a clamp jig 20, an end mill 101, an end mill holder 102, a reference metal 103, a centering part 104, a lifting cylinder 105, a rotation positioning part 106, a dust collector 107, a cover 108, and an induction blow. 109, an attraction blow 110 is provided. In FIG. 1, the detailed configuration of the clamp jig 20 is omitted for simplification of the drawing.

  The workpiece 10 is transferred into the processing apparatus 100 by a robot, for example. Thereafter, the elevating cylinder 105 is raised, and the workpiece 10 stops before being placed on the reference metal 103. The processed surface of the workpiece 10 and the mounting surface of the reference metal 103 are cleaned by air blow (not shown). Thereafter, the workpiece 10 is placed on the reference metal 103, and the centering portion 104 determines the clamp position. Then, the rotation positioning unit 106 determines the rotation position of the workpiece 10 when the end mill 101 processes the seating surface.

  And the workpiece | work 10 is clamped with the clamp jig | tool 20 with the clamp surface which is the upper surface. When the seating of the workpiece 10 on the reference gold 103 is confirmed, the seating surface processing is started. At the time of processing the seat surface, the attracting blow 109 and the attracting blow 110 are turned on, and the dust is collected by the dust collector 107.

  Here, the clamp jig 20 will be described in detail. As shown in FIGS. 2 and 3, the clamp jig 20 can include a rotating member 21, a rotating shaft 22, a first clamp arm 23 a, a second clamp arm 23 b, a biasing member 24, and a backup clamp 25. In FIG. 2, illustration of the rotating member 21, the rotating shaft 22, and the biasing member 24 is omitted for explanation. FIG. 2 shows an example in which a notch 15 is formed in the remaining machining portion 13 of the workpiece 10.

  The clamp jig 20 fixes the workpiece 10 placed on the reference metal 103 between the reference metal 103. In a state where the workpiece 10 is clamped between the reference metal 103 and the clamp jig 20, the workpiece 10 is subjected to a seating process.

  The clamp jig 20 according to the embodiment makes the contact of the first clamp arm 23a and the second clamp arm 23b with the workpiece 10 constant in consideration of the undulation of the clamp surface of the workpiece 10. The rotating member 21 is rotatably supported on the rotating shaft 22. The rotating shaft 22 is provided at a substantially central portion of the rotating member 21.

  As shown in FIG. 3, a first clamp arm 23a and a second clamp arm 23b are attached to both ends of the rotating member 21, respectively. The first clamp arm 23a and the second clamp arm 23b are arranged to face each other with the rotating shaft 22 in between. As shown in FIG. 3, the first clamp arm 23 a and the second clamp arm 23 b abut on the workpiece 10 so as to sandwich the thin portion 14 on the remaining processing portion 13 formed on the workpiece 10 by seating.

  As the first clamp arm 23a and the second clamp arm 23b, for example, a relatively soft metal such as brass or brass, urethane resin, or the like can be used. The tips of the first clamp arm 23a and the second clamp arm 23b are preferably arcuate. Thereby, the deformation | transformation of the workpiece | work 10 by the contact of the 1st clamp arm 23a and the 2nd clamp arm 23b can be suppressed, and damage can be prevented.

  In the clamp jig 20 according to the embodiment, the rotating member 21 rotates around the rotating shaft 22 following the undulation of the upper surface (clamp surface) of the workpiece 10 during the seating surface processing, and the first clamp arm 23a, The workpiece 10 can be fixed by both of the two clamp arms 23b. Thereby, when the workpiece | work 10 is clamped, the bending which arises in the workpiece | work 10 can be suppressed, and it becomes possible to suppress the breakage | damage of the workpiece | work 10, especially the crack in the thin part 14, and a crack.

  Further, the clamp jig 20 includes a backup clamp 25. The backup clamp 25 presses and holds the workpiece 10 between the first clamp arm 23a and the second clamp arm 23b. In the example shown in FIG. 2, the backup clamp 25 is in contact with the clamp surface of the remaining processing portion 13 at an equal distance from the first clamp arm 23 a side and the second clamp arm 23 b side with the thin portion 14 as the center. Thereby, the thin part 14 is protected by the backup clamp 25, and the damage resulting from the cutting force at the time of seating surface processing is suppressed.

  Note that the work 10 has the first clamp arm 23a and the second clamp arm 23b so that the contact of the first clamp arm 23a and the second clamp arm 23b does not become uneven due to the undulation of the clamp surface of the work 10. It is preferable that the backup clamp 25 is brought into contact with the workpiece 10 after being clamped by.

  The backup clamp 25 is an elastic member such as nylon resin or urethane resin. For example, MC nylon (registered trademark) can be used as the backup clamp 25. An urging member 24 is provided between the backup clamp 25 and the rotating member 21. The urging member 24 urges the backup clamp 25 toward the workpiece 10 side.

  As described above, since the backup clamp 25 is an elastic member, the back-up clamp 25 is deformed following the shape of the clamp surface of the remaining processing portion 13 by the biasing force of the biasing member 24. As shown in FIG. 3, the backup clamp 25 is deformed according to the shape of the notch 15. Thereby, protection of the thin part 14 can be performed still more reliably.

  In the example shown in FIG. 3, a spring is used as the biasing member 24, but is not limited to this. For example, as the urging member 24, a drive unit that drives the backup clamp 25 to be pressed against the workpiece 10 may be provided. Thus, by providing the urging member 24, the pressing force applied to the workpiece 10 from the backup clamp 25 can be made uniform.

  As described above, in the clamp jig 20 according to the embodiment, one protrusion 11 is fixed at three points: the clamp arm 23a, the second clamp arm 23b, and the backup clamp 25. Accordingly, it is possible to follow the undulation of the clamp surface of the workpiece 10 during the processing of the seating surface, withstand the cutting load by the end mill 101, and to reliably prevent the workpiece 10 from being damaged.

  In the above-described embodiment, the workpiece 10 is clamped at the three points of the first clamp arm 23a, the second clamp arm 23b, and the backup clamp 25. However, the backup clamp 25 may not be provided. Even when the workpiece 10 is clamped at the two points of the first clamp arm 23a and the second clamp arm 23b, it is possible to prevent the workpiece from being damaged by the undulation of the clamp surface of the workpiece 10.

  Returning to FIG. 1, an example will be described in which the machining apparatus 100 efficiently collects chips generated during seating. As shown in FIG. 1, a jig such as a workpiece 10, a clamp jig 20 that clamps the workpiece 10, and an end mill 101 that performs a seating process of the workpiece 10, so that chips generated by the seating process are not scattered, Covered by a cover 108. An opening 111 is provided in the upper part of the cover 108. An end mill holder 102 that holds the end mill 101 is disposed in the opening 111. The opening 111 also serves as a position for taking out the workpiece 10 by the robot described above.

  The cover 108 is preferably cylindrical so that the air flow in the cover 108 is smooth. An attracting blow 109 is provided around the opening 111. The induction blow 109 is an annular induction blow provided so as to surround the periphery of the opening 111.

  FIG. 4 is a diagram for explaining the attraction blow 109. The induction blow 109 causes compressed air to flow along the shape of the induction blow 109 so as not to scatter chips from the opening 111 of the cover 108 to the outside. Form a flow. The formation of this air flow utilizes the effect that a jet of viscous fluid is attracted to a nearby wall, the so-called Coanda effect. For example, in Japanese Patent Application Laid-Open Nos. 2006-026752 and 2014-104489 Have been described.

  In order to forcibly collect the chips in the cover 108 downward, an attracting blow 110 is provided at the lower part of the cover 108. The attracting blow 110 may have the same configuration as the attracting blow 109. Thereby, scattering of the chip at the time of green processing can be prevented.

  FIG. 5 is a view for explaining an end mill holder 102 used in the processing apparatus 100. The end mill holder 102 forms an air layer in order to prevent chips from scattering during the seating process. As shown in FIG. 5, the end mill holder 102 is provided with an air discharge port 112 so as to surround the end mill 101. On the outer periphery of the air discharge port 112, a C-shaped guide plate 113 that is widened toward the tip of the end mill 101 is provided.

  The compressed air supplied from above the end mill holder 102 is discharged downward from the air discharge port 112 along the inner surface of the guide plate 113. As a result, an air flow is formed as shown by a broken line in FIG. 5, and it is possible to prevent chips from being scattered during the seating surface processing by the end mill 101. In addition, about the technique which forms an air layer and adjusts the flow of dust, it describes in Unexamined-Japanese-Patent No. 2001-108880 and Unexamined-Japanese-Patent No. 07-072511, for example.

  Further, the processing device 100 is provided with an exhaust device (not shown) so that the inside of the cover 108 of the dust collector 107 has a negative pressure. Thus, it becomes possible to collect | recover fine chips efficiently by making the inside of the cover 108 into a negative pressure rather than atmospheric pressure.

  As described above, in the processing apparatus 100, it is possible to increase the recovery rate of the chips scattered when the workpiece 10 is seated, and to suppress the diffusion and accumulation of chips in the equipment and around the processing apparatus. Can do. As a result, it is possible to prevent the work environment and the mobility from deteriorating.

  A part or all of the above embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
A clamp jig that clamps the green compact when the seating is applied to the green compact before sintering that is placed on the reference gold,
A rotating member rotatably supported on a rotating shaft;
Attached to the rotating member with the rotating shaft in between, and abuts on the green compact so as to sandwich a thin portion formed on the green compact during the seating process, and between the reference gold A pair of clamp arms for clamping the green compact with
A clamp jig comprising:

(Appendix 2)
A backup clamp for pressing and holding the compacted body between the clamp arms;
An urging member for urging the backup clamp toward the green compact body;
The clamp jig according to appendix 1, further comprising:

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. The shapes and combinations of the constituent members shown in the embodiments are merely examples, and various changes can be made based on design requirements and the like.

DESCRIPTION OF SYMBOLS 10 Work 11 Protruding part 12 Seat surface process part 13 Process remaining part 14 Thin part 15 Notch part 20 Clamp jig 21 Rotating member 22 Rotating shaft 23a 1st clamp arm 23b 2nd clamp arm 24 Energizing member 25 Backup clamp 100 Processing apparatus 101 End mill 102 End mill holder 103 Reference gold 104 Centering portion 105 Lifting cylinder 106 Rotating positioning portion 107 Dust collector 108 Cover 109 Induction blow 110 Induction blow 111 Opening 112 Air discharge port 113 Guide plate 1 End mill 2 Clamp arm 3 Reference gold 4 Dust collector

Claims (1)

A clamp jig that clamps the green compact when the seating is applied to the green compact before sintering that is placed on the reference gold,
A rotating member rotatably supported on a rotating shaft;
Attached to the rotating member with the rotating shaft in between, and abuts on the green compact so as to sandwich a thin portion formed on the green compact during the seating process, and between the reference gold A pair of clamp arms for clamping the green compact with
A clamp jig comprising:

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